Human body modeling method to simulate the biodynamic characteristics of spine in vivo with different sitting postures.

PubMed

Dong, Rui-Chun; Guo, Li-Xin

2017-11-01

The aim of this study is to model the computational model of seated whole human body including skeleton, muscle, viscera, ligament, intervertebral disc, and skin to predict effect of the factors (sitting postures, muscle and skin, buttocks, viscera, arms, gravity, and boundary conditions) on the biodynamic characteristics of spine. Two finite element models of seated whole body and a large number of finite element models of different ligamentous motion segments were developed and validated. Static, modal, and transient dynamic analyses were performed. The predicted vertical resonant frequency of seated body model was in the range of vertical natural frequency of 4 to 7 Hz. Muscle, buttocks, viscera, and the boundary conditions of buttocks have influence on the vertical resonant frequency of spine. Muscle played a very important role in biodynamic response of spine. Compared with the vertical posture, the posture of lean forward or backward led to an increase in stress on anterior or lateral posterior of lumbar intervertebral discs. This indicated that keeping correct posture could reduce the injury of vibration on lumbar intervertebral disc under whole-body vibration. The driving posture not only reduced the load of spine but also increased the resonant frequency of spine. Copyright © 2017 John Wiley & Sons, Ltd.

[Cervical spine trauma].

PubMed

Yilmaz, U; Hellen, P

2016-08-01

In the emergency department 65 % of spinal injuries and 2-5 % of blunt force injuries involve the cervical spine. Of these injuries approximately 50 % involve C5 and/or C6 and 30 % involve C2. Older patients tend to have higher spinal injuries and younger patients tend to have lower injuries. The anatomical and development-related characteristics of the pediatric spine as well as degenerative and comorbid pathological changes of the spine in the elderly can make the radiological evaluation of spinal injuries difficult with respect to possible trauma sequelae in young and old patients. Two different North American studies have investigated clinical criteria to rule out cervical spine injuries with sufficient certainty and without using imaging. Imaging of cervical trauma should be performed when injuries cannot be clinically excluded according to evidence-based criteria. Degenerative changes and anatomical differences have to be taken into account in the evaluation of imaging of elderly and pediatric patients.

Characteristics of Cervical Spine Injury in Pediatric Patients With Facial Fractures.

PubMed

Halsey, Jordan N; Hoppe, Ian C; Marano, Andrew A; Kordahi, Anthony M; Lee, Edward S; Granick, Mark S

2016-01-01

Cervical spine injury may present with pediatric patients having sustained fractures of the craniofacial skeleton. Management considerations of the cervical spine often take priority to the fractures of the facial skeleton. The goal of this study was to examine this subset of patients with a focus on initial presentation and need for intervention. A retrospective review from 2000 to 2012 of all facial fractures in patients ≤ 18 years at a level 1 trauma center was performed. Patient demographics, location of fractures, and the presence of a cervical spine injury were collected. During this time period, 285 patients met inclusion criteria. Ten patients were found to have a cervical spine injury. Fractures of the zygoma and orbit were significantly associated with a cervical spine injury. Patients with a cervical spine injury had a Glasgow Coma Scale of 11.2 compared with 13.8 in those without (P < 0.05). C1 was injured in 4 patients, C2 in 2 patients, and C3 to C7 in 4 patients. A surgical airway was required in 1 patient, and 6 were intubated in the trauma bay. Fractures of the mandible were significantly associated with injury to C2. Le Fort fractures and palate fractures approached significance with injury to C1. Only 1 patient had neurologic impairment at presentation, manifested as upper extremity parasthesias, and underwent decompression and fusion in the operating room. Those patients admitted (90%) were all admitted for reasons other than management of the cervical spine injury. The majority of patients (70%) were treated with collar immobilization. One patient expired. No patients had a neurologic deficit at the time of discharge. In this study only 1 cervical spine injury necessitated intervention, with an eventual full recovery. Cervical spine injuries presenting with fractures of the facial skeleton appear to be relatively benign in this series; however, care must be taken to identify all such injuries to avoid exacerbation during maneuvers commonly

Winter fasting and refeeding effects on urine characteristics in white-tailed deer

USGS Publications Warehouse

DelGiudice, G.D.; Mech, L.D.; Seal, U.S.; Karns, P.D.

1987-01-01

The effects of dietary protein, fasting, and refeeding on urinary characteristics of 9 captive, female white-tailed deer (Odocoileus virginianus) were studied from 23 February to 3 May 1984. Urinary sodium (na) and potassium (K) were diminished in fasted deer after 2 and 4 weeks. Renal excretion of Na and K were lower, whereas urinary phosphorus (P) was higher in fasted deer compared to deer fed high protein-high energy (HPHE) diets. Urinary P excretion of the fasted deer was also greater than in a low protein-high energy (LPHE)-fed group. Urinary area excretion of fasted deer was similar to that of deer fed low and high protein diets. One fasted deer died during the study and exhibited notably high excretion of urea, Na, K, and calcium (Ca). No effects of the 2 levels of dietary protein on urinary characteristics were detected. Urinary Na:C and K:C ratios wer significantly correlated with Na and K intake. Urinalysis has potential as a sensitive means of monitoring the nutritional status of white-tailed deer. Data are presented as reference values for interpretation of data from deer under less controlled circumstances.

Effect of vertical-tail location on the aerodynamic characteristics at subsonic speeds of a close-coupled canard configuration

NASA Technical Reports Server (NTRS)

Huffman, J. K.

1975-01-01

The effects were studied of various vertical-tail configurations on the longitudinal and lateral directional-stability characteristics of a general research fighter model utilizing wing-body-canard. The study indicates that the addition of the high canard resulted in an increase in total lift at angles of attack above 4 deg with a maximum lift coefficient about twice as large as that for the wing-body configuration. For the wing-body (canard off) configuration, the center-line vertical tail indicates positive vertical-tail effectiveness throughout the test angle-of-attack range; however, for this configuration none of the wing-mounted vertical-tail locations tested resulted in a positive directional-stability increment at the higher angles of attack. For the wing-body-canard configuration several outboard locations of the wing-mounted vertical tails were found.

A True Human Tail in a Neonate: Case report and literature review.

PubMed

Pillai, Mahesh K; Nair, Smitha T

2017-02-01

A true human tail is a benign vestigial caudal cutaneous structure composed of adipose, connective tissue, muscle, vessels, nerves and mechanoreceptors. A true human tail can be distinguished from a pseudotail as the latter is commonly associated with underlying spinal dysraphism, which requires specialised management. True human tails are very rare, with fewer than 40 cases reported to date. We report a healthy one-day-old male newborn who was referred to the Bharath Hospital, Kottayam, Kerala, India, in 2014 with a cutaneous appendage arising from the lumbosacral region. Magnetic resonance imaging of the spine ruled out spinal dysraphism. The appendage was removed by simple surgical excision. Clinicians should emphasise use of 'true tail' and 'pseudotail' as specific disparate terms as the clinical, radiological and histological findings of these conditions differ significantly, along with management strategies and outcomes.

Publication trends in spine research from 2007 to 2016: Comparison of the Orthopaedic Research Society Spine Section and the International Society for the Study of the Lumbar Spine.

PubMed

Martin, John T; Gullbrand, Sarah E; Fields, Aaron J; Purmessur, Devina; Diwan, Ashish D; Oxland, Thomas R; Chiba, Kazuhiro; Guilak, Farshid; Hoyland, Judith A; Iatridis, James C

2018-03-01

This study investigated current trends in spine publications of the membership of Orthopaedic Research Society Spine Section (ORS3) and the more global and clinically focused International Society for the Study of the Lumbar Spine (ISSLS). The PubMed database was probed to quantify trends in the overall number of articles published, the number of journals these articles were published in, and the number of active scientists producing new manuscripts. We also evaluated trends in flagship spine journals ( Spine , European Spine Journal , and The Spine Journal ) and in the Journal of Orthopaedic Research. The total number of active ORS3 and ISSLS authors and articles published have increased over the last 10 years. These articles are being published in hundreds of distinct journals; the number of journals is also increasing. Members of both societies published their work in Spine more than any other journal. Yet, publications in Spine decreased over the last 5 years for both ORS3 and ISSLS members, while those in European Spine Journal , and The Spine Journal remained unchanged. Furthermore, members of both societies have published in Journal of Orthopaedic Research at a consistent level. The increasing number of manuscripts and journals reflects a characteristic intrinsic to science as a whole-the global scientific workforce and output are growing and new journals are being created to accommodate the demand. These data suggest that existing spine journals do not fully serve the diverse publication needs of ORS3 and ISSLS members and highlight an unmet need for consolidating the premiere basic and translational spine research in an open access spine-specific journal. This analysis was an important part of a decision process by the ORS to introduce JOR Spine.

Publication trends in spine research from 2007 to 2016: Comparison of the Orthopaedic Research Society Spine Section and the International Society for the Study of the Lumbar Spine

PubMed Central

Martin, John T.; Gullbrand, Sarah E.; Fields, Aaron J.; Purmessur, Devina; Diwan, Ashish D.; Oxland, Thomas R.; Chiba, Kazuhiro; Guilak, Farshid; Hoyland, Judith A.

2018-01-01

This study investigated current trends in spine publications of the membership of Orthopaedic Research Society Spine Section (ORS3) and the more global and clinically focused International Society for the Study of the Lumbar Spine (ISSLS). The PubMed database was probed to quantify trends in the overall number of articles published, the number of journals these articles were published in, and the number of active scientists producing new manuscripts. We also evaluated trends in flagship spine journals (Spine, European Spine Journal, and The Spine Journal) and in the Journal of Orthopaedic Research. The total number of active ORS3 and ISSLS authors and articles published have increased over the last 10 years. These articles are being published in hundreds of distinct journals; the number of journals is also increasing. Members of both societies published their work in Spine more than any other journal. Yet, publications in Spine decreased over the last 5 years for both ORS3 and ISSLS members, while those in European Spine Journal, and The Spine Journal remained unchanged. Furthermore, members of both societies have published in Journal of Orthopaedic Research at a consistent level. The increasing number of manuscripts and journals reflects a characteristic intrinsic to science as a whole—the global scientific workforce and output are growing and new journals are being created to accommodate the demand. These data suggest that existing spine journals do not fully serve the diverse publication needs of ORS3 and ISSLS members and highlight an unmet need for consolidating the premiere basic and translational spine research in an open access spine‐specific journal. This analysis was an important part of a decision process by the ORS to introduce JOR Spine. PMID:29770804

Characteristics of Hemorrhagic Stroke following Spine and Joint Surgeries.

PubMed

Yang, Fei; Zhao, Jianning; Xu, Haidong

2017-01-01

Hemorrhagic stroke can occur after spine and joint surgeries such as laminectomy, lumbar spinal fusion, tumor resection, and total joint arthroplasty. Although this kind of stroke rarely happens, it may cause severe consequences and high mortality rates. Typical clinical symptoms of hemorrhagic stroke after spine and joint surgeries include headache, vomiting, consciousness disturbance, and mental disorders. It can happen several hours after surgeries. Most bleeding sites are located in cerebellar hemisphere and temporal lobe. A cerebrospinal fluid (CSF) leakage caused by surgeries may be the key to intracranial hemorrhages happening. Early diagnosis and treatments are very important for patients to prevent the further progression of intracranial hemorrhages. Several patients need a hematoma evacuation and their prognosis is not optimistic.

Embryonic development of fin spines in Callorhinchus milii (Holocephali); implications for chondrichthyan fin spine evolution.

PubMed

Jerve, Anna; Johanson, Zerina; Ahlberg, Per; Boisvert, Catherine

2014-01-01

Fin spines are commonly known from fossil gnathostomes (jawed vertebrates) and are usually associated with paired and unpaired fins. They are less common among extant gnathostomes, being restricted to the median fins of certain chondrichthyans (cartilaginous fish), including chimaerids (elephant sharks) and neoselachians (sharks, skates, and rays). Fin spine growth is of great interest and relevance but few studies have considered their evolution and development. We investigated the development of the fin spine of the chimaerid Callorhinchus milii using stained histological sections from a series of larval, hatchling, and adult individuals. The lamellar trunk dentine of the Callorhinchus spine first condenses within the mesenchyme, rather than at the contact surface between mesenchyme and epithelium, in a manner more comparable to dermal bone formation than to normal odontode development. Trabecular dentine forms a small component of the spine under the keel; it is covered externally with a thin layer of lamellar trunk dentine, which is difficult to distinguish in sectioned adult spines. We suggest that the distinctive characteristics of the trunk dentine may reflect an origin through co-option of developmental processes involved in dermal bone formation. Comparison with extant Squalus and a range of fossil chondrichthyans shows that Callorhinchus is more representative than Squalus of generalized chondrichthyan fin-spine architecture, highlighting its value as a developmental model organism. © 2014 Wiley Periodicals, Inc.

Supersonic aerodynamic characteristics of conformal carriage monoplanar circular missile configurations with low-profile quadriform tail fins

NASA Technical Reports Server (NTRS)

Blair, A. B., Jr.

1990-01-01

Wind tunnel tests were conducted on monoplanar circular missile configurations with low-profile quadriform tail fins to provide an aerodynamic data base to study and evaluate air-launched missile candidates for efficient conformal carriage on supersonic-cruise-type aircraft. The tests were conducted at Mach numbers from 1.70 to 2.86 for a constant Reynolds number per foot of 2,000,000. Selected test results are presented to show the effects of tail-fin dihedral angle, wing longitudinal and vertical location, and nose-body strakes on the static longitudinal and lateral-directional aerodynamic stability and control characteristics.

Aerodynamic Characteristics of Three Deep-Stepped Planing-Tail Flying-Boat Hulls

NASA Technical Reports Server (NTRS)

Riebe, John M.; Naeseth, Rodger L.

1947-01-01

An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of three deep-stepped planing-tail flying-boat hulls differing only in the amount of step fairing. The hulls were derived by increasing the unfaired step depth of a planing-tail hull of a previous aerodynamic investigation to a depth about 92 percent of the hull beam. Tests were also made on a transverse-stepped hull with an extended afterbody for the purpose of comparison and in order to extend and verify the results of a previous investigation. The investigation indicated that the extended afterbody hull had a minimum drag coefficient about the same as a conventional hull, 0.0066, and an angle-of-attack range for minimum drag coefficient of 0.0057 which was 14 percent less than the transverse stepped hull with extended afterbody; the hulls with step fairing had up to 44 percent less minimum drag coefficient than the transverse-stepped hull, or slightly more drag than a streamlined body having approximately the same length and volume. Longitudinal and lateral instability varied little with step fairing and was about the same as a conventional hull.

Bony ankylosis of the facet joint of the cervical spine in rheumatoid arthritis: Its characteristics and relationship to the clinical findings.

PubMed

Iizuka, Haku; Iizuka, Yoichi; Okamura, Koichi; Yonemoto, Yukio; Mieda, Tokue; Takagishi, Kenji

2017-09-01

The purpose of this study was to clarify the characteristics of bony ankylosis of the facet joint of the cervical spine in rheumatoid arthritis (RA) patients who required cervical spine surgery, and its relationship to the clinical findings. Eighty consecutive RA patients with cervical spine disorder who received initial surgery were reviewed. The occurrence of bony ankylosis of the facet joint of the cervical spine was investigated using computed tomography (CT) before surgery. We also evaluated the severity of neurological symptoms and the plain wrist radiographs taken before surgery; furthermore, we evaluated each patient's medical history for total knee arthroplasty (TKA) or hip arthroplasty (THA). The preoperative CT imaging demonstrated bony ankylosis of the facet joint of the cervical spine in 45 facet levels of 19 cases (BA + group). In all patients, responsible instability or stenosis was demonstrated just caudal or on the cranial side of those bony ankylosis. Before surgery, the BA + group included significantly more patients showing severe cervical myelopathy (p < 0.05), and significantly more cases showing progressed ankylosis in the wrist joint bilaterally (p < 0.01). There were also significantly more patients who received two or more TKA or THA before the cervical spine surgery in the BA + group (p < 0.01). Bony ankylosis of the facet joint of the cervical spine may be a risk factor of instability or stenosis at the adjacent disc level and severe cervical myelopathy. Furthermore, its ankylosis was demonstrated in RA patients with severe destroyed joints.

Wind-tunnel Investigation of End-plate Effects of Horizontal Tails on a Vertical Tail Compared with Available Theory

NASA Technical Reports Server (NTRS)

Murray, Harry E

1946-01-01

A vertical-tail model with stub fuselage was tested in combination with various simulated horizontal tails to determine the effect of horizontal-tail span and location on the aerodynamic characteristics of the vertical tail. Available theoretical data on end-plate effects were collected and presented in the form most suitable for design purposes. Reasonable agreement was obtained between the measured and theoretical end-plate effects of horizontal tails on vertical tails, and the data indicated that the end-plate effect was determined more by the location of the horizontal tail than by the span of the horizontal tail. The horizontal tail gave most end-plate effect when located near either tip of the vertical tail and, when located near the base of the vertical tail, the end-plate effect was increased by moving the horizontal tail rearward.

Cervical spine injuries in pediatric patients.

PubMed

Platzer, Patrick; Jaindl, Manuela; Thalhammer, Gerhild; Dittrich, Stefan; Kutscha-Lissberg, Florian; Vecsei, Vilmos; Gaebler, Christian

2007-02-01

Cervical spine injuries are uncommon in pediatric trauma patients. Previous studies were often limited by the small numbers of patients available for evaluation. The aim of this study was to determine the incidence and characteristics of pediatric cervical spine injuries at this Level 1 trauma center and to review the authors' experiences with documented cases. This study retrospectively analyzed the clinical records of all pediatric trauma patients with skeletal and/or nonskeletal injuries of the spine that were admitted to this Level 1 trauma center between 1980 and 2004. Those with significant injuries of the cervical spine were identified and included in this study. Pediatric patients were defined as patients younger than the age of 17 years. In addition, they were stratified by age into two study groups: group A included patients aged 8 years or fewer and group B contained patients from the ages of 9 to 16 years. We found 56 pediatric patients with injuries of the cervical spine that met criteria for inclusion. Thirty-one female and 25 male patients with an average age of 8.9 years (range, 1-16 years) sustained significant skeletal and/or nonskeletal injuries of the cervical spine and were entered in this study. Thirty patients (54%) were aged 8 years or fewer and entered into study group A, whereas 26 patients (46%) from the ages of 9 to 16 met criteria for inclusion in study group B. An analysis of data revealed that younger patients (group A) showed significantly more injuries of the upper cervical spine, whereas older children (group B) sustained significantly more injuries of the lower level. Spinal cord injuries without radiographic findings were only found in study group A. In addition, younger children were more likely injured by motor vehicle crashes, whereas older children more commonly sustained C-spine injuries during sports activities. Two-thirds of our patients showed neurologic deficits, and the overall mortality was 28%. The results of our

Experimental Investigation of the Effect of Vertical-tail Size and Length and of Fuselage Shape and Length on the Static Lateral Stability Characteristics of a Model with 45 Degree Sweptback Wing and Tail Surfaces

NASA Technical Reports Server (NTRS)

Queijo, M J; Wolhart, Walter D

1951-01-01

An investigation was made to determine the effects of vertical-tail size and length and of fuselage shape and length on the static lateral stability characteristics of a model with wing and vertical tails having the quarter-chord lines swept back 45 degrees. The results indicate that the directional instability of the various isolated fuselages was about two-thirds as large as that predicted by classical theory.

The degenerative cervical spine.

PubMed

Llopis, E; Belloch, E; León, J P; Higueras, V; Piquer, J

2016-04-01

Imaging techniques provide excellent anatomical images of the cervical spine. The choice to use one technique or another will depend on the clinical scenario and on the treatment options. Plain-film X-rays continue to be fundamental, because they make it possible to evaluate the alignment and bone changes; they are also useful for follow-up after treatment. The better contrast resolution provided by magnetic resonance imaging makes it possible to evaluate the soft tissues, including the intervertebral discs, ligaments, bone marrow, and spinal cord. The role of computed tomography in the study of degenerative disease has changed in recent years owing to its great spatial resolution and its capacity to depict osseous components. In this article, we will review the anatomy and biomechanical characteristics of the cervical spine, and then we provide a more detailed discussion of the degenerative diseases that can affect the cervical spine and their clinical management. Copyright © 2015 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Degenerative Changes of Spine in Helicopter Pilots

PubMed Central

Byeon, Joo Hyeon; Kim, Jung Won; Jeong, Ho Joong; Sim, Young Joo; Kim, Dong Kyu; Choi, Jong Kyoung; Im, Hyoung June

2013-01-01

Objective To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. Methods We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 clerical workers (response rate, 93.6%). Radiographic examinations of the cervical and the lumbar spines were performed after obtaining informed consent in both groups. Degenerative changes of the cervical and lumbar spines were determined using four radiographs per subject, and diagnosed by two independent, blinded radiologists. Results There was no significant difference in general and work-related characteristics except for flight hours and frequency between helicopter pilots and clerical workers. Degenerative changes in the cervical spine were significantly more prevalent in the helicopter pilots compared with control group. In the cervical spine multivariate model, accumulated flight hours (per 100 hours) was associated with degenerative changes. And in the lumbar spine multivariate model, accumulated flight hours (per 100 hours) and age were associated with degenerative changes. Conclusion Accumulated flight hours were associated with degenerative changes of the cervical and lumbar spines in helicopter pilots. PMID:24236259

Population characteristics of a central Appalachian white tailed deer herd

Treesearch

Tyler A. Campbell; Benjamin R. Laseter; W. Mark Ford; Karl V. Miller; Karl V. Miller

2005-01-01

Reliable estimates of white-tailed deer (Odocoileus virginianus) population parameters are needed for effective population management. We used radiotelemetrv to compare survival and cause-specific mortality rates between male and female white-tailed deer and present reproductive data for a high-density deer herd in the central Appalachians of West Virginia during...

A possible instance of sexual dimorphism in the tails of two oviraptorosaur dinosaurs

PubMed Central

IV, W. Scott Persons; Funston, Gregory F.; Currie, Philip J.; Norell, Mark A.

2015-01-01

The hypothesis that oviraptorosaurs used tail-feather displays in courtship behavior previously predicted that oviraptorosaurs would be found to display sexually dimorphic caudal osteology. MPC-D 100/1002 and MPC-D 100/1127 are two specimens of the oviraptorosaur Khaan mckennai. Although similar in absolute size and in virtually all other anatomical details, the anterior haemal spines of MPC-D 100/1002 exceed those of MPC-D 100/1127 in ventral depth and develop a hitherto unreported “spearhead” shape. This dissimilarity cannot be readily explained as pathologic and is too extreme to be reasonably attributed to the amount of individual variation expected among con-specifics. Instead, this discrepancy in haemal spine morphology may be attributable to sexual dimorphism. The haemal spine form of MPC-D 100/1002 offers greater surface area for caudal muscle insertions. On this basis, MPC-D 100/1002 is regarded as most probably male, and MPC-D 100/1127 is regarded as most probably female. PMID:25824625

Acoustic characteristics of underwater tail slaps used by Norwegian and Icelandic killer whales (Orcinus orca) to debilitate herring (Clupea harengus).

PubMed

Simon, Malene; Wahlberg, Magnus; Ugarte, Fernando; Miller, Lee A

2005-06-01

Norwegian killer whales debilitate prey by slapping their tails into herring schools. These underwater tail slaps produce a thud-like sound. It is unclear whether this sound is caused by cavitation and/or physical contact between herring and whale tail. Also the forces causing debilitation of the fish are not understood. Here we present an acoustic analysis of underwater tail slaps using a multi-channel wide (150 kHz) band recording system. Underwater tail slaps produced by Norwegian killer whales generated sounds consisting of multiple pulses with source levels of 186+/-5.4 dB (pp) re.1 microPa at 1 m (+/-1 s.d., N = 4). The -3 dB and 97% energy bandwidths were 36.8+/-22.5 kHz and 130.5+/-17.5 kHz (+/-1 s.d., N = 13), respectively, with a centre frequency of 46.1+/-22.3 kHz. The similarities between the acoustic properties of underwater tail slaps recorded from killer whales in Norway, and thud-like sounds recorded from killer whales in Iceland suggest that Norwegian and Icelandic killer whales use similar hunting techniques. The acoustic characteristics of sounds produced by underwater tail slaps were similar to the ones from other cavitation sound sources described in the literature, both in term of temporal and frequency features as well as in source level. We suggest that multiple factors generated by the tail slaps like particle fluctuations, turbulence, pressure changes and physical impact cause debilitation of herring.

Defensive Medicine in U.S. Spine Neurosurgery.

PubMed

Din, Ryan S; Yan, Sandra C; Cote, David J; Acosta, Michael A; Smith, Timothy R

2017-02-01

Observational cross-sectional survey. To compare defensive practices of U.S. spine and nonspine neurosurgeons in the context of state medical liability risk. Defensive medicine is a commonly reported and costly phenomenon in neurosurgery. Although state liability risk is thought to contribute greatly to defensive practice, variation within neurosurgical specialties has not been well explored. A validated, online survey was sent via email to 3344 members of the American Board of Neurological Surgeons. The instrument contained eight question domains: surgeon characteristics, patient characteristics, practice type, insurance type, surgeon liability profile, basic surgeon reimbursement, surgeon perceptions of medical legal environment, and the practice of defensive medicine. The overall response rate was 30.6% (n = 1026), including 499 neurosurgeons performing mainly spine procedures (48.6%). Spine neurosurgeons had a similar average practice duration as nonspine neurosurgeons (16.6 vs 16.9 years, P = 0.64) and comparable lifetime case volume (4767 vs 4,703, P = 0.71). The average annual malpractice premium for spine neurosurgeons was similar to nonspine neurosurgeons ($104,480.52 vs $101,721.76, P = 0.60). On average, spine neurosurgeons had a significantly higher rate of ordering labs, medications, referrals, procedures, and imaging solely for liability concerns compared with nonspine neurosurgeons (89.2% vs 84.6%, P = 0.031). Multivariate analysis revealed that spine neurosurgeons were roughly 3 times more likely to practice defensively compared with nonspine neurosurgeons (odds ratio, OR = 2.9, P = 0.001) when controlling for high-risk procedures (OR = 7.8, P < 0.001), annual malpractice premium (OR = 3.3, P = 0.01), percentage of patients publicly insured (OR = 1.1, P = 0.80), malpractice claims in the last 3 years (OR = 1.13, P = 0.71), and state medical-legal environment (OR = 1.3, P = 0

Osteoporosis in Cervical Spine Surgery.

PubMed

Guzman, Javier Z; Feldman, Zachary M; McAnany, Steven; Hecht, Andrew C; Qureshi, Sheeraz A; Cho, Samuel K

2016-04-01

Retrospective administrative database analysis. To investigate the effect of osteoporosis (OS) on complications and outcomes in patients undergoing cervical spine surgery. OS is the most prevalent degenerative human bone disease, and spine surgeons will inevitably perform procedures on patients with OS. These patients might present a difficult patient cohort because many fixation techniques depend on bone quality and adequate bone healing--both of which are compromised in OS. The nationwide inpatient sample was queried using the Ninth Revision, Clinical Modification procedural codes for cervical spine procedures and diagnosis codes for degenerative conditions of cervical spine from 2002 to 2011. Patients were separated into two cohorts, those patients with OS and those without OS. Demographics, hospital characteristics, and adjusted complication likelihood were analyzed. Multivariate regression analysis was performed to determine odds of revision surgery in patients with OS. Of all patients undergoing degenerative cervical spine surgery, 2% were identified as having OS (32,557 of a sample of 1,602,129 patients). Osteoporotic patients were more likely to undergo posterior cervical spine fusion when compared with those patients without OS (11.3% vs. 5.4%, P < 0.0001). Moreover, circumferential fusion was performed 3 times more frequently in the osteoporotic cohort. Adjusted complications showed increased odds for postoperative hemorrhage (odds ratio = 1.70, 95% confidence interval = 1.46-1.98, P < 0.0001). Patients with OS stayed in the hospital longer (3.5 vs. 2.5 days, P < 0.0001) and had 30% costlier hospitalizations. Multivariate for revision surgery indicated that osteoporotic patients had significantly increased odds of revision surgery (odds ratio = 1.54, P ≤ 0.0001) when referenced to non-osteoporotic patients undergoing cervical spine surgery. Osteoporotic patients were more likely to undergo revision surgery, have longer

Cortical Composition Hierarchy Driven by Spine Proportion Economical Maximization or Wire Volume Minimization

PubMed Central

Karbowski, Jan

2015-01-01

The structure and quantitative composition of the cerebral cortex are interrelated with its computational capacity. Empirical data analyzed here indicate a certain hierarchy in local cortical composition. Specifically, neural wire, i.e., axons and dendrites take each about 1/3 of cortical space, spines and glia/astrocytes occupy each about (1/3)2, and capillaries around (1/3)4. Moreover, data analysis across species reveals that these fractions are roughly brain size independent, which suggests that they could be in some sense optimal and thus important for brain function. Is there any principle that sets them in this invariant way? This study first builds a model of local circuit in which neural wire, spines, astrocytes, and capillaries are mutually coupled elements and are treated within a single mathematical framework. Next, various forms of wire minimization rule (wire length, surface area, volume, or conduction delays) are analyzed, of which, only minimization of wire volume provides realistic results that are very close to the empirical cortical fractions. As an alternative, a new principle called “spine economy maximization” is proposed and investigated, which is associated with maximization of spine proportion in the cortex per spine size that yields equally good but more robust results. Additionally, a combination of wire cost and spine economy notions is considered as a meta-principle, and it is found that this proposition gives only marginally better results than either pure wire volume minimization or pure spine economy maximization, but only if spine economy component dominates. However, such a combined meta-principle yields much better results than the constraints related solely to minimization of wire length, wire surface area, and conduction delays. Interestingly, the type of spine size distribution also plays a role, and better agreement with the data is achieved for distributions with long tails. In sum, these results suggest that for the

Ultrastructure of Dendritic Spines: Correlation Between Synaptic and Spine Morphologies

PubMed Central

Arellano, Jon I.; Benavides-Piccione, Ruth; DeFelipe, Javier; Yuste, Rafael

2007-01-01

Dendritic spines are critical elements of cortical circuits, since they establish most excitatory synapses. Recent studies have reported correlations between morphological and functional parameters of spines. Specifically, the spine head volume is correlated with the area of the postsynaptic density (PSD), the number of postsynaptic receptors and the ready-releasable pool of transmitter, whereas the length of the spine neck is proportional to the degree of biochemical and electrical isolation of the spine from its parent dendrite. Therefore, the morphology of a spine could determine its synaptic strength and learning rules. To better understand the natural variability of neocortical spine morphologies, we used a combination of gold-toned Golgi impregnations and serial thin-section electron microscopy and performed three-dimensional reconstructions of spines from layer 2/3 pyramidal cells from mouse visual cortex. We characterized the structure and synaptic features of 144 completed reconstructed spines, and analyzed their morphologies according to their positions. For all morphological parameters analyzed, spines exhibited a continuum of variability, without clearly distinguishable subtypes of spines or clear dependence of their morphologies on their distance to the soma. On average, the spine head volume was correlated strongly with PSD area and weakly with neck diameter, but not with neck length. The large morphological diversity suggests an equally large variability of synaptic strength and learning rules. PMID:18982124

Statistical analysis of dendritic spine distributions in rat hippocampal cultures

PubMed Central

2013-01-01

Background Dendritic spines serve as key computational structures in brain plasticity. Much remains to be learned about their spatial and temporal distribution among neurons. Our aim in this study was to perform exploratory analyses based on the population distributions of dendritic spines with regard to their morphological characteristics and period of growth in dissociated hippocampal neurons. We fit a log-linear model to the contingency table of spine features such as spine type and distance from the soma to first determine which features were important in modeling the spines, as well as the relationships between such features. A multinomial logistic regression was then used to predict the spine types using the features suggested by the log-linear model, along with neighboring spine information. Finally, an important variant of Ripley’s K-function applicable to linear networks was used to study the spatial distribution of spines along dendrites. Results Our study indicated that in the culture system, (i) dendritic spine densities were "completely spatially random", (ii) spine type and distance from the soma were independent quantities, and most importantly, (iii) spines had a tendency to cluster with other spines of the same type. Conclusions Although these results may vary with other systems, our primary contribution is the set of statistical tools for morphological modeling of spines which can be used to assess neuronal cultures following gene manipulation such as RNAi, and to study induced pluripotent stem cells differentiated to neurons. PMID:24088199

Remote control canard missile with a free-rolling tail brake torque system

NASA Technical Reports Server (NTRS)

Blair, A. B., Jr.

1981-01-01

An experimental wind-tunnel investigation has been conducted at supersonic Mach numbers to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed and free-rolling tail-fin afterbodies. Mechanical coupling effects of the free-rolling tail afterbody were investigated using an electronic/electromagnetic brake system that provides arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail-roll rate. Results are summarized to show the effects of fixed and free-rolling tail-fin afterbodies that include simulated measured bearing friction torques on the longitudinal and lateral-directional aerodynamic characteristics.

Influence of landscape characteristics on migration strategies of white-tailed deer

USGS Publications Warehouse

Grovenburg, T.W.; Jacques, C.N.; Klaver, R.W.; Deperno, C.S.; Brinkman, T.J.; Swanson, C.C.; Jenks, J.A.

2011-01-01

A trade-off exists for migrating animals as to whether to migrate or remain residents. Few studies have documented relationships between landscape variables and deer migration strategies. From 2000 to 2007 we captured 267 adult female white-tailed deer (Odocoileus virginianus) at 7 study sites in Minnesota and South Dakota and monitored 149 individuals through ≥3 seasonal migration periods (585 deer-migration seasons). All deer classified as obligate migrators with ≥3 migrations (range 3–9 migration seasons) maintained their obligate status for the duration of the study. Multinomial logistic odds ratios from generalized estimating equations indicated that the odds of being a resident increased by 1.4 and 1.3 per 1-unit increase in forest patch density and mean area, respectively, compared to migrating deer. Odds of being an obligate migrator increased by 0.7 and 0.8 per 1-unit decrease in forest patch density and mean area, respectively, compared to resident or conditional migrating deer. Areas inhabited by resident deer were characterized by greater number of forest patches per 100 ha and larger mean forest patch area than conditional and obligate migrant areas. Odds of migrating increased by 1.1 per 1-unit increase in deer winter severity index. Migration behavior of white-tailed deer varied among regions, and land-cover and landscape characteristics provided predictive indicators of migration strategies for deer that could have important implications for conservation, metapopulation dynamics, and species management.

Supersonic aerodynamic characteristics of a maneuvering canard-controlled missile with fixed and free-rolling tail fins

NASA Technical Reports Server (NTRS)

Blair, A. B., Jr.

1990-01-01

Wind tunnel investigations were conducted on a generic cruciform canard-controlled missile configuration. The model featured fixed or free-rolling tail-fin afterbodies to provide an expanded aerodynamic data base with particular emphasis on alleviating large induced rolling moments and/or for providing canard roll control throughout the entire test angle-of-attack range. The tests were conducted in the NASA Langley Unitary Plan Wind Tunnel at Mach numbers from 2.50 to 3.50 at a constant Reynolds number per foot of 2.00 x 10 to the 6th. Selected test results are presented to show the effects of a fixed or free-rolling tail-fin afterbody on the static longitudinal and lateral-directional aerodynamic characteristics of a canard-controlled missile with pitch, yaw, and roll control at model roll angles of 0 deg and 45 deg.

Static Longitudinal Stability and Control Characteristics of an Unswept Wing and Unswept Horizontal-Tail Configuration at Mach Numbers from 0.70 to 2.22

NASA Technical Reports Server (NTRS)

Peterson, Victor L.; Menees, Gene P.

1959-01-01

Results of an investigation of the static longitudinal stability and control characteristics of an aspect-ratio-3.1, unswept wing configuration equipped with an aspect-ratio-4, unswept horizontal tail are presented without analysis for the Mach number range from 0.70 to 2.22. The hinge line of the all-movable horizontal tail was in the extended wing chord plane, 1.66 wing mean aerodynamic chords behind the reference center of moments. The ratio of the area of the exposed horizontal-tail panels to the total area of the wing was 13.3 percent and the ratio of the total areas was 19.9 percent. Data are presented at angles of attack ranging"from -6 deg to +18 deg for the horizontal tail set at angles ranging from +5 deg to -20 deg and for the tail removed.

Fifty top-cited spine articles from mainland China: A citation analysis.

PubMed

Wu, Yaohong; Zhao, Yachao; Lin, Linghan; Lu, Zhijun; Guo, Zhaoyang; Li, Xiaoming; Chen, Rongchun; Ma, Huasong

2018-02-01

Objective To identify the 50 top-cited spine articles from mainland China and to analyze their main characteristics. Methods Web of Science was used to identify the 50 top-cited spine articles from mainland China in 27 spine-related journals. The title, year of publication, number of citations, journal, anatomic focus, subspecialty, evidence level, city, institution and author were recorded. Results The top 50 articles had 29-122 citations and were published in 11 English-language journals; most (32) were published in the 2000s. The journal Spine had the largest number of articles and The Lancet had the highest impact factor. The lumber spine was the most discussed anatomic area (18). Degenerative spine disease was the most common subspecialty topic (22). Most articles were clinical studies (29); the others were basic research (21). Level IV was the most common evidence level (17). Conclusions This list indicates the most influential articles from mainland China in the global spine research community. Identification of these articles provides insights into the trends in spine care in mainland China and the historical contributions of researchers from mainland China to the international spine research field.

Flight Investigation of Effect of Various Vertical-Tail Modifications on the Directional Stability and Control Characteristics of the P-63A-1 Airplane (AAF No. 42-68889)

NASA Technical Reports Server (NTRS)

Johnson, Harold I.

1946-01-01

Because the results of preliminary flight tests had indicated. the P-63A-1 airplane possessed insufficient directional stability, the NACA and the manufacturer (Bell Aircraft Corporation) suggested three vertical-tail modifications to remedy the deficiencies in the directional characteristics. These modifications included an enlarged vertical tail formed by adding a tip extension to the original vertical tail, a large sharp-edge ventral fin, and a small dorsal fin. The enlarged vertical tail involved only a slight increase in total vertical-tail area from 23.73 to 26.58 square feet but a relatively much larger increase in geometric aspect ratio from 1.24 to 1.73 based on height and area above the horizontal tail. At the request of the Air Material Command, Army Air Forces, flight tests were made to determine the effect of these modifications and of some combinations of these modifications on the directional stability and control characteristics of the airplane, In all, six different vertical-tail. configurations were investigated to determine the lateral and directional oscillation characteristics of the airplane, the sideslip characteristics, the yaw due to ailerons in rudder-fixed rolls from turns and pull-outs, the trim changes due to speed changes; and the trim changes due to power changes. Results of the tests showed that the enlarged vertical tail approximately doubled the directional stability of the airplane and that the pilots considered the directional stability provided by the enlarged vertical tail to be satisfactory. Calculations based on sideslip data obtained at an indicated airspeed of 300 miles per hour showed that the directional stability of the airplane with the original vertical tail corresponded to a value of 0(sub n beta) of -0.00056 whereas for the enlarged vertical tail the estimated va1ue of C(sub n beta) was -0.00130, The ventral fin was found to increase by a moderate amount the directional stability of the airplane with the original

Heavy Tail Behavior of Rainfall Extremes across Germany

NASA Astrophysics Data System (ADS)

Castellarin, A.; Kreibich, H.; Vorogushyn, S.; Merz, B.

2017-12-01

Distributions are termed heavy-tailed if extreme values are more likely than would be predicted by probability distributions that have exponential asymptotic behavior. Heavy-tail behavior often leads to surprise, because historical observations can be a poor guide for the future. Heavy-tail behavior seems to be widespread for hydro-meteorological extremes, such as extreme rainfall and flood events. To date there have been only vague hints to explain under which conditions these extremes show heavy-tail behavior. We use an observational data set consisting of 11 climate variables at 1440 stations across Germany. This homogenized, gap-free data set covers 110 years (1901-2010) at daily resolution. We estimate the upper tail behavior, including its uncertainty interval, of daily precipitation extremes for the 1,440 stations at the annual and seasonal time scales. Different tail indicators are tested, including the shape parameter of the Generalized Extreme Value distribution, the upper tail ratio and the obesity index. In a further step, we explore to which extent the tail behavior can be explained by geographical and climate factors. A large number of characteristics is derived, such as station elevation, degree of continentality, aridity, measures for quantifying the variability of humidity and wind velocity, or event-triggering large-scale atmospheric situation. The link between the upper tail behavior and these characteristics is investigated via data mining methods capable of detecting non-linear relationships in large data sets. This exceptionally rich observational data set, in terms of number of stations, length of time series and number of explaining variables, allows insights into the upper tail behavior which is rarely possible given the typical observational data sets available.

Cervical spine injuries in pediatric athletes: mechanisms and management.

PubMed

Jagannathan, Jay; Dumont, Aaron S; Prevedello, Daniel M; Shaffrey, Christopher I; Jane, John A

2006-10-15

Sports-related injuries to the spine, although relatively rare compared with head injuries, contribute to significant morbidity and mortality in children. The reported incidence of traumatic cervical spine injury in pediatric athletes varies, and most studies are limited because of the low prevalence of injury. The anatomical and biomechanical differences between the immature spine of pediatric patients and the mature spine of adults that make pediatric patients more susceptible to injury include a greater mobility of the spine due to ligamentous laxity, shallow angulations of facet joints, immature development of neck musculature, and incomplete ossification of the vertebrae. As a result of these differences, 60 to 80% of all pediatric vertebral injuries occur in the cervical region. Understanding pediatric injury biomechanics in the cervical spine is important to the neurosurgeon, because coaches, parents, and athletes who place themselves in positions known to be associated with spinal cord injury (SCI) run a higher risk of such injury and paralysis. The mechanisms of SCI can be broadly subclassified into five types: axial loading, dislocation, lateral bending, rotation, and hyperflexion/hyperextension, although severe injuries often result from a combination of more than one of these subtypes. The aim of this review was to detail the characteristics and management of pediatric cervical spine injury.

Spine device clinical trials: design and sponsorship.

PubMed

Cher, Daniel J; Capobianco, Robyn A

2015-05-01

Multicenter prospective randomized clinical trials represent the best evidence to support the safety and effectiveness of medical devices. Industry sponsorship of multicenter clinical trials is purported to lead to bias. To determine what proportion of spine device-related trials are industry-sponsored and the effect of industry sponsorship on trial design. Analysis of data from a publicly available clinical trials database. Clinical trials of spine devices registered on ClinicalTrials.gov, a publicly accessible trial database, were evaluated in terms of design, number and location of study centers, and sample size. The relationship between trial design characteristics and study sponsorship was evaluated using logistic regression and general linear models. One thousand six hundred thrity-eight studies were retrieved from ClinicalTrials.gov using the search term "spine." Of the 367 trials that focused on spine surgery, 200 (54.5%) specifically studied devices for spine surgery and 167 (45.5%) focused on other issues related to spine surgery. Compared with nondevice trials, device trials were far more likely to be sponsored by the industry (74% vs. 22.2%, odds ratio (OR) 9.9 [95% confidence interval 6.1-16.3]). Industry-sponsored device trials were more likely multicenter (80% vs. 29%, OR 9.8 [4.8-21.1]) and had approximately four times as many participating study centers (p<.0001) and larger sample sizes. There were very few US-based multicenter randomized trials of spine devices not sponsored by the industry. Most device-related spine research is industry-sponsored. Multicenter trials are more likely to be industry-sponsored. These findings suggest that previously published studies showing larger effect sizes in industry-sponsored vs. nonindustry-sponsored studies may be biased as a result of failure to take into account the marked differences in design and purpose. Copyright © 2015 Elsevier Inc. All rights reserved.

A review on in situ phytoremediation of mine tailings.

PubMed

Wang, Li; Ji, Bin; Hu, Yuehua; Liu, Runqing; Sun, Wei

2017-10-01

Mine tailings are detrimental to natural plant growth due to their physicochemical characteristics, such as high pH, high salinity, low water retention capacity, high heavy metal concentrations, and deficiencies in soil organic matter and fertility. Thus, the remediation of mine tailings has become a key issue in environmental science and engineering. Phytoremediation, an in situ cost-effective technology, is emerging as the most promising remediation method for mine tailings by introducing tolerant plant species. It is particularly effective in dealing with large-area mine tailings with shallow contamination of organic, nutrient and metal pollutants. In this review, the background, concepts and applications of phytoremediation are comprehensively discussed. Furthermore, proper amendments used to improve the physical, chemical and biological properties of mine tailings are systematically reviewed and compared. Emphasis is placed on the types and characteristics of tolerant plants and their role in phytoremediation. Moreover, the role of microorganisms and their mechanism in phytoremediation are also discussed in-depth. Copyright © 2017 Elsevier Ltd. All rights reserved.

Buckling Collapse of Midcervical Spine Secondary to Neurofibromatosis.

PubMed

Shah, Kunal C; Gadia, Akshay; Nagad, Premik; Bhojraj, Shekhar; Nene, Abhay

2018-06-01

Buckling collapse is the term typically used to describe severe kyphosis >100 degrees, characteristically seen in thoracolumbar tuberculosis. Neurofibromatosis is rarely associated with severe cervical kyphosis. Dystrophic changes in vertebra make surgical correction and fusion challenging. Single-stage cervical osteotomies (e.g., pedicle subtraction osteotomy, vertebral column resection) are commonly done in cervicothoracic junction. However, it is technically challenging and associated with high risk of vertebral artery injury, neural injury, etc. when performed in higher cervical spine. Hence in our case we did a staged procedure performing circumferential osteotomy for buckling kyphosis in the midcervical spine. Because it involved midcervical spine and there was no chin-to-chest deformity, we preferred the anterior-posterior-anterior sequence. Copyright © 2018 Elsevier Inc. All rights reserved.

The continued burden of spine fractures after motor vehicle crashes.

PubMed

Wang, Marjorie C; Pintar, Frank; Yoganandan, Narayan; Maiman, Dennis J

2009-02-01

Spine fractures are a significant cause of morbidity and mortality after motor vehicle crashes (MVCs). Public health interventions, such as the National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standards, have led to an increase in automobiles with air bags and the increased use of seat belts to lessen injuries sustained from MVCs. The purpose of this study was to evaluate secular trends in the occurrence of spine fractures associated with MVCs and evaluate the association between air bag and seat belt use with spine fractures. Using the Crash Outcome Data Evaluation System, a database of the police reports of all MVCs in Wisconsin linked to hospital records, the authors studied the occurrence of spine fractures and seat belt and air bag use from 1994 to 2002. Demographic information and crash characteristics were obtained from the police reports. Injury characteristics were determined using International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) hospital discharge codes. From 1994 to 2002, there were 29,860 hospital admissions associated with automobile or truck crashes. There were 20,276 drivers or front-seat passengers 16 years of age and older who were not missing ICD-9-CM discharge codes, seat belt or air bag data, and who had not been ejected from the vehicle. Of these, 2530 (12.5%) sustained a spine fracture. The occurrence of spine fractures increased over the study period, and the use of a seat belt plus air bag, and of air bags alone also increased during this period. However, the occurrence of severe spine fractures (Abbreviated Injury Scale Score > or =3) did not significantly increase over the study period. The use of both seat belt and air bag was associated with decreased odds of a spine fracture. Use of an air bag alone was associated with increased odds of a severe thoracic, but not cervical spine fracture. Among drivers and front-seat passengers admitted to the hospital after MVCs, the

A simulation study of spine biofidelity in the hybrid-III 6-year-old ATD.

PubMed

Wu, Jun; Cao, Libo; Reed, Matthew P; Hu, Jingwen

2013-01-01

Because of the lack of pediatric biomechanical data, Hybrid-III (HIII) child anthropomorphic test devices (ATDs) are essentially scaled from the mid-size male ATD based on the geometric considerations. These ATDs inherit a rigid thoracic spine from the adult HIII ATDs, which has been criticized as unrealistic. Therefore, the objective of this study was to explore possible design modifications for improving the spine biofidelity of the HIII 6-year-old ATD. A previously developed and validated HIII 6-year-old MADYMO ATD model was used as the baseline model to investigate the effects of design modifications on the spine biofidelity of the current ATD. Several sets of child volunteer and cadaver test data were considered as the design targets, including child volunteer low-speed crash test data, pediatric cadaver cervical spine tensile test data, and child cadaver crash test data. ATD design modifications include adding an additional joint to the thoracic spine region and changing the joint characteristics at the cervical and lumbar spine regions. Optimization techniques were used to match simulation results to each set of test results. The results indicate that the translational characteristics of the cervical and lumbar spine in the current child ATD need to be reduced to achieve realistic spine flexibility. Adding an additional joint at the thoracic spine region with degree of freedom in both flexion/extension and tension would significantly improve the ATD biofidelity in terms of predicting the overall spine curvature and head excursion in frontal crashes. Future ATD spine modification should focus on reducing the neck and lumbar tension stiffness and adding additional flexibility both in flexion/extension and tension at the thoracic spine region. The child ATD model developed in this study can be used as an important tool to improve child ATD biofidelity and child restraint system design in motor vehicle crashes.

Surgical Site Infections in Pediatric Spine Surgery: Comparative Microbiology of Patients with Idiopathic and Nonidiopathic Etiologies of Spine Deformity.

PubMed

Maesani, Matthieu; Doit, Catherine; Lorrot, Mathie; Vitoux, Christine; Hilly, Julie; Michelet, Daphné; Vidal, Christophe; Julien-Marsollier, Florence; Ilharreborde, Brice; Mazda, Keyvan; Bonacorsi, Stéphane; Dahmani, Souhayl

2016-01-01

Surgical site infections (SSIs) are a concern in pediatric spine surgery with unusually high rates for a clean surgery and especially for patients with deformity of nonidiopathic etiology. Microbiologic differences between etiologies of spine deformities have been poorly investigated. We reviewed all cases of SSI in spinal surgery between 2007 and 2011. Characteristics of cases and of bacteria according to the etiology of the spine disease were investigated. Of 496 surgeries, we identified 51 SSIs (10.3%) in 49 patients. Staphylococcus aureus was the most frequent pathogen whatever the etiology (n = 31, 61% of infection cases). The second most frequent pathogens vary according to the etiology of the spine deformity. It was Gram-negative bacilli (GNB) in nonidiopathic cases (n = 19, 45% of cases) and anaerobe in idiopathic cases (n = 8, 38% of cases), particularly Gram-positive anaerobic cocci (n = 5, 24% of cases). Infection rate was 6.8% in cases with idiopathic spine disease (n = 21) and 15.9% in cases with nonidiopathic spine disease (n = 30). Nonidiopathic cases were more frequently male with lower weight. American Society of Anesthesiologists score was more often greater than 2, they had more frequently sacral implants and postoperative intensive care unit stay. GNB were significantly associated with a nonidiopathic etiology, low weight, younger age and sacral fusion. SSIs were polymicrobial in 31% of cases with a mean of 1.4 species per infection cases. S. aureus is the first cause of SSI in pediatric spine surgery. However, Gram-positive anaerobic cocci should be taken into account in idiopathic patients and GNB in nonidiopathic patients when considering antibiotic prophylaxis and curative treatment.

A model of activity-dependent changes in dendritic spine density and spine structure.

PubMed

Crook, S M; Dur-E-Ahmad, M; Baer, S M

2007-10-01

Recent evidence indicates that the morphology and density of dendritic spines are regulated during synaptic plasticity. See, for instance, a review by Hayashi and Majewska [9]. In this work, we extend previous modeling studies [27] by combining a model for activity-dependent spine density with one for calcium-mediated spine stem restructuring. The model is based on the standard dimensionless cable equation, which represents the change in the membrane potential in a passive dendrite. Additional equations characterize the change in spine density along the dendrite, the current balance equation for an individual spine head, the change in calcium concentration in the spine head, and the dynamics of spine stem resistance. We use computational studies to investigate the changes in spine density and structure for differing synaptic inputs and demonstrate the effects of these changes on the input-output properties of the dendritic branch. Moderate amounts of high-frequency synaptic activation to dendritic spines result in an increase in spine stem resistance that is correlated with spine stem elongation. In addition, the spine density increases both inside and outside the input region. The model is formulated so that this long-term potentiation-inducing stimulus eventually leads to structural stability. In contrast, a prolonged low-frequency stimulation paradigm that would typically induce long-term depression results in a decrease in stem resistance (correlated with stem shortening) and an eventual decrease in spine density.

Authorship Trends in Spine Publications from 2000 to 2015.

PubMed

Haws, Brittany E; Khechen, Benjamin; Movassaghi, Kamran; Yom, Kelly H; Guntin, Jordan A; Cardinal, Kaitlyn L; Shoshana, Noah B; Singh, Kern

2018-02-06

Literature review. To examine changes in authorship characteristics for Spine publications from the year 2000-2015. Scientific publications are considered an indication of academic achievement for physicians. Recently, authorship trends have been investigated, however, limited information is available on this topic within spine-specific literature. Original research articles published in Spine in the years 2000, 2005, 2010, and 2015 were evaluated. Authorship characteristics were collected for each article, including the number of authors and institutions per publication, first and last author gender, publication origin, and highest degree held by the first and last author. Trends over time were analyzed using numeric and visual descriptive analyses including percentages, means, standard deviations, and graphs. An average of 506 articles per year were published in Spine during the years 2000, 2005, 2010, and 2015. The number of articles written by ≥ 10 authors increased during this time (0.9% to 14.4%). There was a substantial increase in the number of multiple institutional affiliations (33.6% to 68.7%) and articles originating from outside North America (47.6% to 55.7%) from 2000 to 2015. The percentage of first authors with bachelor's degrees was higher in 2015 (6.6%) as compared to 2000 (1.4%), and more last authors were identified as MD/PhDs in 2015 (19.2%) than in 2000 (10.0%). Similar female representation was noted for first and last authorship for all years evaluated. The results of this study demonstrate increases in authors per article published in Spine from 2000 to 2015. Additionally, first authors were more likely to hold bachelor's degrees over time. This may be attributed to increasing competition in spine-related fields, necessitating earlier research exposure to aid in academic achievement. Interestingly, the percentage of female authorship has not changed significantly over time, in contrast with much of the previous literature. 2.

Computed Tomography (CT) - Spine

MedlinePlus

... Resources Professions Site Index A-Z Computed Tomography (CT) - Spine Computed tomography (CT) of the spine is ... of CT Scanning of the Spine? What is CT Scanning of the Spine? Computed tomography, more commonly ...

Variations in 30-day readmissions and length of stay among spine surgeons: a national study of elective spine surgery among US Medicare beneficiaries.

PubMed

Singh, Siddhartha; Sparapani, Rodney; Wang, Marjorie C

2018-06-01

OBJECTIVE Pay-for-performance programs are targeting hospital readmissions. These programs have an underlying assumption that readmissions are due to provider practice patterns that can be modified by a reduction in reimbursement. However, there are limited data to support the role of providers in influencing readmissions. To study this, the authors examined variations in readmission rates by spine surgeon within 30 days among Medicare beneficiaries undergoing elective lumbar spine surgery for degenerative conditions. METHODS The authors applied validated ICD-9-CM algorithms to 2003-2007 Medicare data to select beneficiaries undergoing elective inpatient lumbar spine surgery for degenerative conditions. Mixed models, adjusting for patient demographics, comorbidities, and surgery type, were used to estimate risk of 30-day readmission by the surgeon. Length of stay (LOS) was also studied using these same models. RESULTS A total of 39,884 beneficiaries were operated on by 3987 spine surgeons. The mean readmission rate was 7.2%. The mean LOS was 3.1 days. After adjusting for patient characteristics and surgery type, 1 surgeon had readmission rates significantly below the mean, and only 5 surgeons had readmission rates significantly above the mean. In contrast, for LOS, the patients of 288 surgeons (7.2%) had LOS significantly lower than the mean, and the patients of 397 surgeons (10.0%) had LOS significantly above the mean. These findings were robust to adjustments for surgeon characteristics and clustering by hospital. Similarly, hospital characteristics were not significantly associated with readmission rates, but LOS was associated with hospital for-profit status and size. CONCLUSIONS The authors found almost no variations in readmission rates by surgeon. These findings suggest that surgeon practice patterns do not affect the risk of readmission. Likewise, no significant variation in readmission rates by hospital characteristics were found. Strategies to reduce

3D morphology-based clustering and simulation of human pyramidal cell dendritic spines.

PubMed

Luengo-Sanchez, Sergio; Fernaud-Espinosa, Isabel; Bielza, Concha; Benavides-Piccione, Ruth; Larrañaga, Pedro; DeFelipe, Javier

2018-06-13

The dendritic spines of pyramidal neurons are the targets of most excitatory synapses in the cerebral cortex. They have a wide variety of morphologies, and their morphology appears to be critical from the functional point of view. To further characterize dendritic spine geometry, we used in this paper over 7,000 individually 3D reconstructed dendritic spines from human cortical pyramidal neurons to group dendritic spines using model-based clustering. This approach uncovered six separate groups of human dendritic spines. To better understand the differences between these groups, the discriminative characteristics of each group were identified as a set of rules. Model-based clustering was also useful for simulating accurate 3D virtual representations of spines that matched the morphological definitions of each cluster. This mathematical approach could provide a useful tool for theoretical predictions on the functional features of human pyramidal neurons based on the morphology of dendritic spines.

Validity of the Digital Inclinometer and iPhone When Measuring Thoracic Spine Rotation.

PubMed

Bucke, Jonathan; Spencer, Simon; Fawcett, Louise; Sonvico, Lawrence; Rushton, Alison; Heneghan, Nicola R

2017-09-01

  Spinal axial rotation is required for many functional and sporting activities. Eighty percent of axial rotation occurs in the thoracic spine. Existing measures of thoracic spine rotation commonly involve laboratory equipment, use a seated position, and include lumbar motion. A simple performance-based outcome measure would allow clinicians to evaluate isolated thoracic spine rotation. Currently, no valid measure exists.   To explore the criterion and concurrent validity of a digital inclinometer (DI) and iPhone Clinometer app (iPhone) for measuring thoracic spine rotation using the heel-sit position.   Controlled laboratory study.   University laboratory.   A total of 23 asymptomatic healthy participants (14 men, 9 women; age = 25.82 ± 4.28 years, height = 170.26 ± 8.01 cm, mass = 67.50 ± 9.46 kg, body mass index = 23.26 ± 2.79) were recruited from a student population.   We took DI and iPhone measurements of thoracic spine rotation in the heel-sit position concurrently with dual-motion analysis (laboratory measure) and ultrasound imaging of the underlying bony tissue motion (reference standard). To determine the criterion and concurrent validity, we used the Pearson product moment correlation coefficient (r, 2 tailed) and Bland-Altman plots.   The DI (r = 0.88, P < .001) and iPhone (r = 0.88, P < .001) demonstrated strong criterion validity. Both also had strong concurrent validity (r = 0.98, P < .001). Bland-Altman plots illustrated mean differences of 5.82° (95% confidence interval [CI] = 20.37°, -8.73°) and 4.94° (95% CI = 19.23°, -9.35°) between the DI and iPhone, respectively, and the reference standard and 0.87° (95% CI = 6.79°, -5.05°) between the DI and iPhone.   The DI and iPhone provided valid measures of thoracic spine rotation in the heel-sit position. Both can be used in clinical practice to assess thoracic spine rotation, which may be valuable when evaluating thoracic dysfunction.

Spatial and Working Memory Is Linked to Spine Density and Mushroom Spines

PubMed Central

Aher, Yogesh D.; Sase, Ajinkya; Gröger, Marion; Mokhtar, Maher; Höger, Harald; Lubec, Gert

2015-01-01

Background Changes in synaptic structure and efficacy including dendritic spine number and morphology have been shown to underlie neuronal activity and size. Moreover, the shapes of individual dendritic spines were proposed to correlate with their capacity for structural change. Spine numbers and morphology were reported to parallel memory formation in the rat using a water maze but, so far, there is no information on spine counts or shape in the radial arm maze (RAM), a frequently used paradigm for the evaluation of complex memory formation in the rodent. Methods 24 male Sprague-Dawley rats were divided into three groups, 8 were trained, 8 remained untrained in the RAM and 8 rats served as cage controls. Dendritic spine numbers and individual spine forms were counted in CA1, CA3 areas and dentate gyrus of hippocampus using a DIL dye method with subsequent quantification by the Neuronstudio software and the image J program. Results Working memory errors (WME) and latency in the RAM were decreased along the training period indicating that animals performed the task. Total spine density was significantly increased following training in the RAM as compared to untrained rats and cage controls. The number of mushroom spines was significantly increased in the trained as compared to untrained and cage controls. Negative significant correlations between spine density and WME were observed in CA1 basal dendrites and in CA3 apical and basal dendrites. In addition, there was a significant negative correlation between spine density and latency in CA3 basal dendrites. Conclusion The study shows that spine numbers are significantly increased in the trained group, an observation that may suggest the use of this method representing a morphological parameter for memory formation studies in the RAM. Herein, correlations between WME and latency in the RAM and spine density revealed a link between spine numbers and performance in the RAM. PMID:26469788

Environmental Risk Assessment System for Phosphogypsum Tailing Dams

PubMed Central

Sun, Xin; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

2013-01-01

This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams. PMID:24382947

Environmental risk assessment system for phosphogypsum tailing dams.

PubMed

Sun, Xin; Ning, Ping; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

2013-01-01

This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

The Burden of Clostridium difficile after Cervical Spine Surgery.

PubMed

Guzman, Javier Z; Skovrlj, Branko; Rothenberg, Edward S; Lu, Young; McAnany, Steven; Cho, Samuel K; Hecht, Andrew C; Qureshi, Sheeraz A

2016-06-01

Study Design Retrospective database analysis. Objective The purpose of this study is to investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after cervical spine surgery. Methods A total of 1,602,130 cervical spine surgeries from the Nationwide Inpatient Sample database from 2002 to 2011 were included. Patients were included for study based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for cervical spine surgery for degenerative spine diagnoses. Baseline patient characteristics were determined. Multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. Results Incidence of C. difficile infection in postoperative cervical spine surgery hospitalizations is 0.08%, significantly increased since 2002 (p < 0.0001). The odds of postoperative C. difficile infection were significantly increased in patients with comorbidities such as congestive heart failure, renal failure, and perivascular disease. Circumferential cervical fusion (odds ratio [OR] = 2.93, p < 0.0001) increased the likelihood of developing C. difficile infection after degenerative cervical spine surgery. C. difficile infection after cervical spine surgery results in extended length of stay (p < 0.0001) and increased hospital costs (p < 0.0001). Mortality rate in patients who develop C. difficile after cervical spine surgery is nearly 8% versus 0.19% otherwise (p < 0.0001). Moreover, multivariate analysis revealed C. difficile to be a significant predictor of inpatient mortality (OR = 3.99, p < 0.0001). Conclusions C. difficile increases the risk of in-hospital mortality and costs approximately $6,830,695 per year to manage in patients undergoing elective cervical spine surgery. Patients with comorbidities such as renal failure or congestive heart failure have increased probability of developing infection

Cooling Characteristics of an Experimental Tail-pipe Burner with an Annular Cooling-air Passage

NASA Technical Reports Server (NTRS)

Kaufman, Harold R; Koffel, William K

1952-01-01

The effects of tail-pipe fuel-air ratio (exhaust-gas temperatures from approximately 3060 degrees to 3825 degrees R), radial distributiion of tail-pipe fuel flow, and mass flow of combustion gas and the inside wall were determined for an experimental tail-pipe burner cooled by air flowing through and insulated cooling-air to combustion gas mass flow from 0.066 to 0.192 were also determined.

Conspicuous carotenoid-based pelvic spine ornament in three-spined stickleback populations—occurrence and inheritance

PubMed Central

Amundsen, CR; Gjøen, HM; Larsen, B; Egeland, ES

2015-01-01

Reports on reddish carotenoid-based ornaments in female three-spined sticklebacks (Gasterosteus aculeatus) are few, despite the large interest in the species’ behaviour, ornamentation, morphology and evolution. We sampled sticklebacks from 17 sites in north-western Europe in this first extensive study on the occurrence of carotenoid-based female pelvic spines and throat ornaments. The field results showed that females, and males, with reddish spines were found in all 17 populations. Specimens of both sexes with conspicuous red spines were found in several of the sites. The pelvic spines of males were more intensely red compared to the females’ spines, and large specimens were more red than small ones. Fish infected with the tapeworm (Schistocephalus solidus) had drabber spines than uninfected fish. Both sexes had red spines both during and after the spawning period, but the intensity of the red colour was more exaggerated during the spawning period. As opposed to pelvic spines, no sign of red colour at the throat was observed in any female from any of the 17 populations. A rearing experiment was carried out to estimate a potential genetic component of the pelvic spine ornament by artificial crossing and rearing of 15 family groups during a 12 months period. The results indicated that the genetic component of the red colour at the spines was low or close to zero. Although reddish pelvic spines seem common in populations of stickleback, the potential adaptive function of the reddish pelvic spines remains largely unexplained. PMID:25861558

The effect of canard and vertical tails on the aerodynamic characteristics of a model with a 59 deg sweptback wing at a Mach number of 0.30

NASA Technical Reports Server (NTRS)

Henderson, W. P.

1974-01-01

An investigation has been conducted to determine the effects of canard, canard location, vertical tails, and vertical-tail location on the aerodynamic characteristics of a model having a 59 deg sweptback wing. The investigation was conducted at a Mach number of 0.30, at angles of attack up to 22 deg and at sideslip angles of 0 deg and plus or minus 5 deg. The results of the study indicate that adding the canard to the model had only a slight effect on the lift at the lower angles of attack. At the higher angles of attack there is a significant effect of canard height on lift, canard in the high location (above the wing chord plane) resulting in the highest lifts. The lift drag characteristics are predicted well for the configuration with the mid or high canard locations by combining a potential flow solution on the canard with a potential plus vortex solution on the wing. Variations in the height significantly affect the pitching-moment characteristics of the configuration; the configuration with the low or mid canard location exhibits an increase in stability at the higher lift coefficients, whereas the configuration with the high canard exhibits pitch-up. Adding the vertical tails in the outboard location caused a significant loss in lift at the higher angles of attack; this lift loss was eliminated by moving the vertical tails inboard.

An experimental study of the effect of tail configuration on the spinning characteristics of general aviation aircraft. M.S. Thesis; [static wind tunnel force measurements

NASA Technical Reports Server (NTRS)

Ballin, M. G.

1982-01-01

The feasibility of using static wind tunnel tests to obtain information about spin damping characteristics of an isolated general aviation aircraft tail was investigated. A representative tail section was oriented to the tunnel free streamline at angles simulating an equilibrium spin. A full range of normally encountered spin conditions was employed. Results of parametric studies performed to determine the effect of spin damping on several tail design parameters show satisfactory agreement with NASA rotary balance tests. Wing and body interference effects are present in the NASA studies at steep spin attitudes, but agreement improves with increasing pitch angle and spin rate, suggesting that rotational flow effects are minimal. Vertical position of the horizontal stabilizer is found to be a primary parameter affecting yaw damping, and horizontal tail chordwise position induces a substantial effect on pitching moment.

Postoperative 3D spine reconstruction by navigating partitioning manifolds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadoury, Samuel, E-mail: samuel.kadoury@polymtl.ca; Labelle, Hubert, E-mail: hubert.labelle@recherche-ste-justine.qc.ca; Parent, Stefan, E-mail: stefan.parent@umontreal.ca

Purpose: The postoperative evaluation of scoliosis patients undergoing corrective treatment is an important task to assess the strategy of the spinal surgery. Using accurate 3D geometric models of the patient’s spine is essential to measure longitudinal changes in the patient’s anatomy. On the other hand, reconstructing the spine in 3D from postoperative radiographs is a challenging problem due to the presence of instrumentation (metallic rods and screws) occluding vertebrae on the spine. Methods: This paper describes the reconstruction problem by searching for the optimal model within a manifold space of articulated spines learned from a training dataset of pathological casesmore » who underwent surgery. The manifold structure is implemented based on a multilevel manifold ensemble to structure the data, incorporating connections between nodes within a single manifold, in addition to connections between different multilevel manifolds, representing subregions with similar characteristics. Results: The reconstruction pipeline was evaluated on x-ray datasets from both preoperative patients and patients with spinal surgery. By comparing the method to ground-truth models, a 3D reconstruction accuracy of 2.24 ± 0.90 mm was obtained from 30 postoperative scoliotic patients, while handling patients with highly deformed spines. Conclusions: This paper illustrates how this manifold model can accurately identify similar spine models by navigating in the low-dimensional space, as well as computing nonlinear charts within local neighborhoods of the embedded space during the testing phase. This technique allows postoperative follow-ups of spinal surgery using personalized 3D spine models and assess surgical strategies for spinal deformities.« less

Dumbbell-Shaped Epidural Cavernous Hemangioma in the Thoracic Spine Mimicking Schwannoma.

PubMed

Wang, Shantao; Wang, Mingwei; Wang, Fuchao; Yuan, Xunhui; Xiao, Hang; Bai, Yun'an; Liu, Fucun

2016-10-01

Dumbbell-shaped epidural cavernous hemangiomas (CHs) are extremely rare, and they are easily misdiagnosed as spinal schwannomas. Herein, the authors report 1 rare case of dumbbell-shaped epidural CH in the thoracic spine. To the best of our knowledge, only a few cases of dumbbell-shaped epidural CHs in thoracic spine have been reported. Furthermore, the clinical characteristics and treatments for spinal epidural CHs were investigated and reviewed.

Leaching characteristics of vanadium in mine tailings and soils near a vanadium titanomagnetite mining site.

PubMed

Yang, Jinyan; Tang, Ya; Yang, Kai; Rouff, Ashaki A; Elzinga, Evert J; Huang, Jen-How

2014-01-15

A series of column leaching experiments were performed to understand the leaching behaviour and the potential environmental risk of vanadium in a Panzhihua soil and vanadium titanomagnetite mine tailings. Results from sequential extraction experiments indicated that the mobility of vanadium in both the soil and the mine tailings was low, with <1% of the total vanadium readily mobilised. Column experiments revealed that only <0.1% of vanadium in the soil and mine tailing was leachable. The vanadium concentrations in the soil leachates did not vary considerably, but decreased with the leachate volume in the mine tailing leachates. This suggests that there was a smaller pool of leachable vanadium in the mine tailings compared to that in the soil. Drought and rewetting increased the vanadium concentrations in the soil and mine tailing leachates from 20μgL(-1) to 50-90μgL(-1), indicating the potential for high vanadium release following periods of drought. Experiments with soil columns overlain with 4, 8 and 20% volume mine tailings/volume soil exhibited very similar vanadium leaching behaviour. These results suggest that the transport of vanadium to the subsurface is controlled primarily by the leaching processes occurring in soils. Copyright © 2013 Elsevier B.V. All rights reserved.

Cervical spine CT scan

MedlinePlus

... cervical spine; Computed tomography scan of cervical spine; CT scan of cervical spine; Neck CT scan ... table that slides into the center of the CT scanner. Once you are inside the scanner, the ...

Flight investigation of the effect of tail configuration on stall, spin, and recovery characteristics of a low-wing general aviation research airplane

NASA Technical Reports Server (NTRS)

Stough, H. Paul, III; Patton, James M., Jr.; Sliwa, Steven M.

1987-01-01

Flight tests were performed to investigate the stall, spin, and recovery characteristics of a low-wing, single-engine, light airplane with four interchangeable tail configurations. The four tail configurations were evaluated for effects of varying mass distribution, center-of-gravity position, and control inputs. The airplane tended to roll-off at the stall. Variations in tail configuration produced spins ranging from 40 deg to 60 deg angle of attack and turn rates of about 145 to 208 deg/sec. Some unrecoverable flat spins were encountered which required use of the airplane spin chute for recovery. For recoverable spins, antispin rudder followed by forward wheel with ailerons centered provided the quickest spin recovery. The moderate spin modes agreed very well with those predicted from spin-tunnel model tests, however, the flat spin was at a lower angle of attack and a slower rotation rate than indicated by the model tests.

Diagnostic Simulations of the Lunar Exosphere using Coma and Tail

NASA Astrophysics Data System (ADS)

Lee, Dong Wook; Kim, Sang J.

2017-10-01

The characteristics of the lunar exosphere can be constrained by comparing simulated models with observational data of the coma and tail (Lee et al., JGR, 2011); and thus far a few independent approaches on this issue have been performed and presented in the literature. Since there are two-different observational constraints for the lunar exosphere, it is interesting to find the best exospheric model that can account for the observed characteristics of the coma and tail. Considering various initial conditions of different sources and space weather, we present preliminary time-dependent simulations between the initial and final stages of the development of the lunar tail. Based on an updated 3-D model, we are planning to conduct numerous simulations to constrain the best model parameters from the coma images obtained from coronagraph observations supported by a NASA monitoring program (Morgan, Killen, and Potter, AGU, 2015) and future tail data.

Lumbar spine CT scan

MedlinePlus

CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... CT scans rapidly makes detailed pictures of the lower back. The test may be used to look for: ...

Spread of plague among black-tailed prairie dogs is associated with colony spatial characteristics

USGS Publications Warehouse

Johnson, T.L.; Cully, J.F.; Collinge, S.K.; Ray, C.; Frey, C.M.; Sandercock, B.K.

2011-01-01

Sylvatic plague (Yersinia pestis) is an exotic pathogen that is highly virulent in black-tailed prairie dogs (Cynomys ludovicianus) and causes widespread colony losses and individual mortality rates >95%. We investigated colony spatial characteristics that may influence inter-colony transmission of plague at 3 prairie dog colony complexes in the Great Plains. The 4 spatial characteristics we considered include: colony size, Euclidean distance to nearest neighboring colony, colony proximity index, and distance to nearest drainage (dispersal) corridor. We used multi-state mark-recapture models to determine the relationship between these colony characteristics and probability of plague transmission among prairie dog colonies. Annual mapping of colonies and mark-recapture analyses of disease dynamics in natural colonies led to 4 main results: 1) plague outbreaks exhibited high spatial and temporal variation, 2) the site of initiation of epizootic plague may have substantially influenced the subsequent inter-colony spread of plague, 3) the long-term effect of plague on individual colonies differed among sites because of how individuals and colonies were distributed, and 4) colony spatial characteristics were related to the probability of infection at all sites although the relative importance and direction of relationships varied among sites. Our findings suggest that conventional prairie dog conservation management strategies, including promoting large, highly connected colonies, may need to be altered in the presence of plague. ?? 2011 The Wildlife Society.

Spine centerline extraction and efficient spine reading of MRI and CT data

NASA Astrophysics Data System (ADS)

Lorenz, C.; Vogt, N.; Börnert, P.; Brosch, T.

2018-03-01

Radiological assessment of the spine is performed regularly in the context of orthopedics, neurology, oncology, and trauma management. Due to the extension and curved geometry of the spinal column, reading is time-consuming and requires substantial user interaction to navigate through the data during inspection. In this paper a spine geometry guided viewing approach is proposed facilitating reading by reducing the degrees of freedom to be manipulated during inspection of the data. The method is using the spine centerline as a representation of the spine geometry. We assume that renderings most useful for reading are those that can be locally defined based on a rotation and translation relative to the spine centerline. The resulting renderings conserve locally the relation to the spine and lead to curved planar reformats that can be adjusted using a small set of parameters to minimize user interaction. The spine centerline is extracted by an automated image to image foveal fully convolutional neural network (FFCN) based approach. The network consists of three parallel convolutional pathways working on different levels of resolution and processed fields of view. The outputs of the parallel pathways are combined by a subsequent feature integration pathway to yield the (final) centerline probability map, which is converted into a set of spine centerline points. The network has been trained separately using two data set types, one comprising a mixture of T1 and T2 weighted spine MR images and one using CT image data. We achieve an average centerline position error of 1.7 mm for MR and 0.9 mm for CT and a DICE coefficient of 0.84 for MR and 0.95 for CT. Based on the thus obtained centerline viewing and multi-planar reformatting can be easily facilitated.

Altitude Performance Characteristics of Tail-pipe Burner with Convergingconical Burner Section on J47 Turbojet Engine

NASA Technical Reports Server (NTRS)

Prince, William R; Mcaulay, John E

1950-01-01

An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel. Performance data were obtained with a tail-pipe burner having a converging conical burner section installed on an axial-flow-compressor type turbojet engine over a range of simulated flight conditions and tail-pipe fuel-air ratios with a fixed-area exhaust nozzle. A maximum tail-pipe combustion efficiency of 0.86 was obtained at an altitude of 15,000 feet and a flight Mach number of 0.23. Tail-pipe burner operation was possible up to an altitude of 45,000 feet at a flight Mach number of 0.23.

Thoracic spine x-ray

MedlinePlus

Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... The test is done in a hospital radiology department or in the health care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

The spine neck filters membrane potentials.

PubMed

Araya, Roberto; Jiang, Jiang; Eisenthal, Kenneth B; Yuste, Rafael

2006-11-21

Dendritic spines receive most synaptic inputs in the forebrain. Their morphology, with a spine head isolated from the dendrite by a slender neck, indicates a potential role in isolating inputs. Indeed, biochemical compartmentalization occurs at spine heads because of the diffusional bottleneck created by the spine neck. Here we investigate whether the spine neck also isolates inputs electrically. Using two-photon uncaging of glutamate on spine heads from mouse layer-5 neocortical pyramidal cells, we find that the amplitude of uncaging potentials at the soma is inversely proportional to neck length. This effect is strong and independent of the position of the spine in the dendritic tree and size of the spine head. Moreover, spines with long necks are electrically silent at the soma, although their heads are activated by the uncaging event, as determined with calcium imaging. Finally, second harmonic measurements of membrane potential reveal an attenuation of somatic voltages into the spine head, an attenuation directly proportional to neck length. We conclude that the spine neck plays an electrical role in the transmission of membrane potentials, isolating synapses electrically.

The spine neck filters membrane potentials

PubMed Central

Araya, Roberto; Jiang, Jiang; Eisenthal, Kenneth B.; Yuste, Rafael

2006-01-01

Dendritic spines receive most synaptic inputs in the forebrain. Their morphology, with a spine head isolated from the dendrite by a slender neck, indicates a potential role in isolating inputs. Indeed, biochemical compartmentalization occurs at spine heads because of the diffusional bottleneck created by the spine neck. Here we investigate whether the spine neck also isolates inputs electrically. Using two-photon uncaging of glutamate on spine heads from mouse layer-5 neocortical pyramidal cells, we find that the amplitude of uncaging potentials at the soma is inversely proportional to neck length. This effect is strong and independent of the position of the spine in the dendritic tree and size of the spine head. Moreover, spines with long necks are electrically silent at the soma, although their heads are activated by the uncaging event, as determined with calcium imaging. Finally, second harmonic measurements of membrane potential reveal an attenuation of somatic voltages into the spine head, an attenuation directly proportional to neck length. We conclude that the spine neck plays an electrical role in the transmission of membrane potentials, isolating synapses electrically. PMID:17093040

Electrical Advantages of Dendritic Spines

PubMed Central

Gulledge, Allan T.; Carnevale, Nicholas T.; Stuart, Greg J.

2012-01-01

Many neurons receive excitatory glutamatergic input almost exclusively onto dendritic spines. In the absence of spines, the amplitudes and kinetics of excitatory postsynaptic potentials (EPSPs) at the site of synaptic input are highly variable and depend on dendritic location. We hypothesized that dendritic spines standardize the local geometry at the site of synaptic input, thereby reducing location-dependent variability of local EPSP properties. We tested this hypothesis using computational models of simplified and morphologically realistic spiny neurons that allow direct comparison of EPSPs generated on spine heads with EPSPs generated on dendritic shafts at the same dendritic locations. In all morphologies tested, spines greatly reduced location-dependent variability of local EPSP amplitude and kinetics, while having minimal impact on EPSPs measured at the soma. Spine-dependent standardization of local EPSP properties persisted across a range of physiologically relevant spine neck resistances, and in models with variable neck resistances. By reducing the variability of local EPSPs, spines standardized synaptic activation of NMDA receptors and voltage-gated calcium channels. Furthermore, spines enhanced activation of NMDA receptors and facilitated the generation of NMDA spikes and axonal action potentials in response to synaptic input. Finally, we show that dynamic regulation of spine neck geometry can preserve local EPSP properties following plasticity-driven changes in synaptic strength, but is inefficient in modifying the amplitude of EPSPs in other cellular compartments. These observations suggest that one function of dendritic spines is to standardize local EPSP properties throughout the dendritic tree, thereby allowing neurons to use similar voltage-sensitive postsynaptic mechanisms at all dendritic locations. PMID:22532875

The international spine registry SPINE TANGO: status quo and first results

PubMed Central

Melloh, Markus; Aghayev, Emin; Zweig, Thomas; Barz, Thomas; Theis, Jean-Claude; Chavanne, Albert; Grob, Dieter; Aebi, Max; Roeder, Christoph

2008-01-01

With an official life time of over 5 years, Spine Tango can meanwhile be considered the first international spine registry. In this paper we present an overview of frequency statistics of Spine Tango for demonstrating the genesis of questionnaire development and the constantly increasing activity in the registry. Results from two exemplar studies serve for showing concepts of data analysis applied to a spine registry. Between 2002 and 2006, about 6,000 datasets were submitted by 25 centres. Descriptive analyses were performed for demographic, surgical and follow-up data of three generations of the Spine Tango surgery and follow-up forms. The two exemplar studies used multiple linear regression models to identify potential predictor variables for the occurrence of dura lesions in posterior spinal fusion, and to evaluate which covariates influenced the length of hospital stay. Over the study period there was a rise in median patient age from 52.3 to 58.6 years in the Spine Tango data pool and an increasing percentage of degenerative diseases as main pathology from 59.9 to 71.4%. Posterior decompression was the most frequent surgical measure. About one-third of all patients had documented follow-ups. The complication rate remained below 10%. The exemplar studies identified “centre of intervention” and “number of segments of fusion” as predictors of the occurrence of dura lesions in posterior spinal fusion surgery. Length of hospital stay among patients with posterior fusion was significantly influenced by “centre of intervention”, “surgeon credentials”, “number of segments of fusion”, “age group” and “sex”. Data analysis from Spine Tango is possible but complicated by the incompatibility of questionnaire generations 1 and 2 with the more recent generation 3. Although descriptive and also analytic studies at evidence level 2++ can be performed, findings cannot yet be generalised to any specific country or patient population. Current

Diversity of Spine Synapses in Animals

PubMed Central

Wang, Ya-Xian; Mattson, Mark P.; Yao, Pamela J.

2016-01-01

Here we examine the structure of the various types of spine synapses throughout the animal kingdom. Based on available evidence, we suggest that there are two major categories of spine synapses: invaginating and non-invaginating, with distributions that vary among different groups of animals. In the simplest living animals with definitive nerve cells and synapses, the cnidarians and ctenophores, most chemical synapses do not form spine synapses. But some cnidarians have invaginating spine synapses, especially in photoreceptor terminals of motile cnidarians with highly complex visual organs, and also in some mainly sessile cnidarians with rapid prey capture reflexes. This association of invaginating spine synapses with complex sensory inputs is retained in the evolution of higher animals in photoreceptor terminals and some mechanoreceptor synapses. In contrast to invaginating spine synapse, non-invaginating spine synapses have been described only in animals with bilateral symmetry, heads and brains, associated with greater complexity in neural connections. This is apparent already in the simplest bilaterians, the flatworms, which can have well-developed non-invaginating spine synapses in some cases. Non-invaginating spine synapses diversify in higher animal groups. We also discuss the functional advantages of having synapses on spines and more specifically, on invaginating spines. And finally we discuss pathologies associated with spine synapses, concentrating on those systems and diseases where invaginating spine synapses are involved. PMID:27230661

Dendritic spine remodeling following early and late Rac1 inhibition after spinal cord injury: evidence for a pain biomarker

PubMed Central

Zhao, Peng; Hill, Myriam; Liu, Shujun; Chen, Lubin; Bangalore, Lakshmi; Waxman, Stephen G.

2016-01-01

Neuropathic pain is a significant complication following spinal cord injury (SCI) with few effective treatments. Drug development for neuropathic pain often fails because preclinical studies do not always translate well to clinical conditions. Identification of biological characteristics predictive of disease state or drug responsiveness could facilitate more effective clinical translation. Emerging evidence indicates a strong correlation between dendritic spine dysgenesis and neuropathic pain. Because dendritic spines are located on dorsal horn neurons within the spinal cord nociceptive system, dendritic spine remodeling provides a unique opportunity to understand sensory dysfunction after SCI. In this study, we provide support for the postulate that dendritic spine profiles can serve as biomarkers for neuropathic pain. We show that dendritic spine profiles after SCI change to a dysgenic state that is characteristic of neuropathic pain in a Rac1-dependent manner. Suppression of the dysgenic state through inhibition of Rac1 activity is accompanied by attenuation of neuropathic pain. Both dendritic spine dysgenesis and neuropathic pain return when inhibition of Rac1 activity is lifted. These findings suggest the utility of dendritic spines as structural biomarkers for neuropathic pain. PMID:26936986

Subsonic and supersonic longitudinal stability and control characteristics of an aft-tail fighter configuration with cambered and uncambered wings and cambered fuselage

NASA Technical Reports Server (NTRS)

Dollyhigh, S. M.

1977-01-01

The longitudinal aerodynamic characteristics of a fighter airplane concept has been determined through an investigation over a Mach number range from 0.50 to 2.16. The configuration incorporates a cambered fuselage with a single external compression horizontal ramp inlet, a clipped arrow wing, twin horizontal tails, and a single vertical tail. The wing camber surface was optimized in drag due to lift and was designed to be self trimming at Mach 1.40 and at a lift coefficient of 0.20. The fuselage was cambered to preserve the design wing loadings on the part of the theoretical wing enclosed by the fuselage. An uncambered of flat wing of the same planform and thickness ratio distribution was also tested.

Musical representation of dendritic spine distribution: a new exploratory tool.

PubMed

Toharia, Pablo; Morales, Juan; de Juan, Octavio; Fernaud, Isabel; Rodríguez, Angel; DeFelipe, Javier

2014-04-01

Dendritic spines are small protrusions along the dendrites of many types of neurons in the central nervous system and represent the major target of excitatory synapses. For this reason, numerous anatomical, physiological and computational studies have focused on these structures. In the cerebral cortex the most abundant and characteristic neuronal type are pyramidal cells (about 85 % of all neurons) and their dendritic spines are the main postsynaptic target of excitatory glutamatergic synapses. Thus, our understanding of the synaptic organization of the cerebral cortex largely depends on the knowledge regarding synaptic inputs to dendritic spines of pyramidal cells. Much of the structural data on dendritic spines produced by modern neuroscience involves the quantitative analysis of image stacks from light and electron microscopy, using standard statistical and mathematical tools and software developed to this end. Here, we present a new method with musical feedback for exploring dendritic spine morphology and distribution patterns in pyramidal neurons. We demonstrate that audio analysis of spiny dendrites with apparently similar morphology may "sound" quite different, revealing anatomical substrates that are not apparent from simple visual inspection. These morphological/music translations may serve as a guide for further mathematical analysis of the design of the pyramidal neurons and of spiny dendrites in general.

[Distribution characteristic and current situation of soil rare earth contamination in the Bayan Obo mining area and Baotou tailing reservoir in Inner Mongolia].

PubMed

Guo, Wei; Fu, Rui-ying; Zhao, Ren-xin; Zhao, Wen-jing; Guo, Jiang-yuan; Zhang, Jun

2013-05-01

The pollution status and distribution characteristic of rare earth elements in soil were analyzed around Bayan Obo mining area and Baotou tailing reservoir located in Inner Mongolia grassland ecosystem, aiming at grasping the overall situation of grassland ecosystem pollution caused by rare earth elements and providing basic information as well as theoretical basis. The results indicated that seven rare earth elements in soils from different directions of Baotou tailing reservoir accumulated to a certain extent compared to the soil background value of Inner Mongolia. The pollution degree was Ce > La > Nd > Pr > Sm > Y > Eu. Within 50 m from the edge of tailing reservoir, soil rare earth contamination was the most serious, with the concentrations of La, Ce, Pr, Nd, Sm, Eu and Y reaching 11,45.0 mg x kg(-1), 23,636.0 mg x kg(-1), 4568.16 mg x kg(-1) , 6855.51 mg x kg(-1), 582.18 mg x kg(-1), 94.21 mg x kg(-1)), and 136.25 mg x kg(-1), respectively. Owing to the dominant wind direction of northwest, soils from the southeast were contaminated most seriously. For Bayan Obo mining area, the concentrations of seven rare earth elements in soil from the mining area were significantly higher than those of other areas investigated, with the concentrations of La, Ce, Pr, Nd, Sm, Eu and Y reaching 3112.56 mg x kg(-1), 7142.12 mg x kg(-1), 1467.12 mg x kg(-1), 2552.80 mg x kg(-1), 210.80 mg x kg(-1), 36.20 mg x kg(-1) and 63.22 mg x kg(-1), respectively. The soils of six areas of Bayan Obo mining area were all contaminated by rare earth elements, and the contamination degree was in the order of mining area > outside the dump > east side of the railway > the dump > outside the urban area > west side of the railway. Besides, the transportation of rare earth ore led to the soil rare earth contamination along the railway, and the distribution characteristic of rare earth elements in soils along the railway was affected by the dominant wind direction of northwest. Baotou tailing

Effect of Tail Dihedral on Lateral Control Effectiveness at High Subsonic Speeds of Differentially Deflected Horizontal-Tail Surfaces on a Configuration having a Thin Highly Tapered Wing

NASA Technical Reports Server (NTRS)

Fournier, Paul G.

1959-01-01

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel to determine the effect of tail dihedral on lateral control effectiveness of a complete-model configuration having differentially deflected horizontal-tail surfaces. Limited tests were made to determine the lateral characteristics as well as the longitudinal characteristics in sideslip. The wing had an aspect ratio of 3, a taper ratio of 0.14, 28.80 deg sweep of the quarter-chord line with zero sweep at the 80-percent-chord line, and NACA 65A004 airfoil sections. The test Mach number range extended from 0.60 to 0.92. There are only small variations in the roll effectiveness parameter C(sub iota delta) with negative tail dihedral angle. The tail size used on the test model, however, is perhaps inadequate for providing the roll rates specified by current military requirements at subsonic speeds. The lateral aerodynamic characteristics were essentially constant throughout the range of sideslip angle from 12 deg to -12 deg. A general increase in yawing moment was noted with increased negative dihedral throughout the Mach number range.

Altitude Performance Characteristics of Tail-pipe Burner with Variable-area Exhaust Nozzle

NASA Technical Reports Server (NTRS)

Jansen, Emmert T; Thorman, H Carl

1950-01-01

An investigation was conducted in the NACA Lewis altitude wind tunnel to determine effect of altitude and flight Mach number on performance of tail-pipe burner equipped with variable-area exhaust nozzle and installed on full-scale turbojet engine. At a given flight Mach number, with constant exhaust-gas and turbine-outlet temperatures, increasing altitude lowered the tail-pipe combustion efficiency and raised the specific fuel consumption while the augmented thrust ratio remained approximately constant. At a given altitude, increasing flight Mach number raised the combustion efficiency and augmented thrust ratio and lowered the specific fuel consumption.

Whole Body Vibration Training is Osteogenic at the Spine in College-Age Men and Women.

PubMed

Ligouri, Gianna C; Shoepe, Todd C; Almstedt, Hawley C

2012-03-01

Osteoporosis is a chronic skeletal disease characterized by low bone mass which is currently challenging the American health care system. Maximizing peak bone mass early in life is a cost-effective method for preventing osteoporosis. Whole body vibration (WBV) is a novel exercise method with the potential to increase bone mass, therefore optimizing peak bone and decreasing the risk for osteoporotic fracture. The aim of this investigation was to evaluate changes in bone mineral density at the hip, spine, and whole body in college-age men and women who underwent a WBV training protocol. Active men (n=6) and women (n=4), ages 18-22 participated in the WBV training; while an additional 14 volunteers (1 male, 13 female) served as controls. All participants completed baseline and follow-up questionnaires to assess health history, physical activity, dietary intake, and menstrual history. The WBV training program, using a Vibraflex 550, incorporated squats, stiff-leg dead lifts, stationary lunges, push-up holds, bent-over rows, and jumps performed on the platform, and occurred 3 times a week, for 12 weeks. Dual energy x-ray absorptiometry (Hologic Explorer, Waltham, MA, USA) was used to assess bone mineral density (BMD, g/cm(2)). A two-tailed, t-test identified significantly different changes in BMD between the WBV and control groups at the lateral spine (average change of 0.022 vs. -0.015 g/cm(2)). The WBV group experienced a 2.7% and 1.0% increase in BMD in the lateral spine and posterior-anterior spine while the control group decreased 1.9% and 0.9%, respectively. Results indicate that 12 weeks of WBV training was osteogenic at the spine in college-age men and women.

Intravital imaging of dendritic spine plasticity

PubMed Central

Sau Wan Lai, Cora

2014-01-01

Abstract Dendritic spines are the postsynaptic part of most excitatory synapses in the mammalian brain. Recent works have suggested that the structural and functional plasticity of dendritic spines have been associated with information coding and memories. Advances in imaging and labeling techniques enable the study of dendritic spine dynamics in vivo. This perspective focuses on intravital imaging studies of dendritic spine plasticity in the neocortex. I will introduce imaging tools for studying spine dynamics and will further review current findings on spine structure and function under various physiological and pathological conditions. PMID:28243511

Near-tail reconnection as the cause of cometary tail disconnections

NASA Technical Reports Server (NTRS)

Russell, C. T.; Saunders, M. A.; Phillips, J. L.; Fedder, J. A.

1986-01-01

In a cometary tail disconnection event the plasma tail appears to separate from the coma and to accelerate away from it. As this occurs a new tail begins to form. It is proposed that these disconnections arise in a manner analogous to geomagnetic substorms, i.e., by the formation of a strongly reconnecting region in the near tail that forms a magnetic island in the coma and ejects the plasma tail by strengthening the magnetic 'slingshot' within the tail. This reconnection process may be triggered by several different processes, such as interplanetary shocks or variations in the Alfven Mach number.

Fractures of the cervical spine

PubMed Central

Marcon, Raphael Martus; Cristante, Alexandre Fogaça; Teixeira, William Jacobsen; Narasaki, Douglas Kenji; Oliveira, Reginaldo Perilo; de Barros Filho, Tarcísio Eloy Pessoa

2013-01-01

OBJECTIVES: The aim of this study was to review the literature on cervical spine fractures. METHODS: The literature on the diagnosis, classification, and treatment of lower and upper cervical fractures and dislocations was reviewed. RESULTS: Fractures of the cervical spine may be present in polytraumatized patients and should be suspected in patients complaining of neck pain. These fractures are more common in men approximately 30 years of age and are most often caused by automobile accidents. The cervical spine is divided into the upper cervical spine (occiput-C2) and the lower cervical spine (C3-C7), according to anatomical differences. Fractures in the upper cervical spine include fractures of the occipital condyle and the atlas, atlanto-axial dislocations, fractures of the odontoid process, and hangman's fractures in the C2 segment. These fractures are characterized based on specific classifications. In the lower cervical spine, fractures follow the same pattern as in other segments of the spine; currently, the most widely used classification is the SLIC (Subaxial Injury Classification), which predicts the prognosis of an injury based on morphology, the integrity of the disc-ligamentous complex, and the patient's neurological status. It is important to correctly classify the fracture to ensure appropriate treatment. Nerve or spinal cord injuries, pseudarthrosis or malunion, and postoperative infection are the main complications of cervical spine fractures. CONCLUSIONS: Fractures of the cervical spine are potentially serious and devastating if not properly treated. Achieving the correct diagnosis and classification of a lesion is the first step toward identifying the most appropriate treatment, which can be either surgical or conservative. PMID:24270959

Cidaroids spines facing ocean acidification.

PubMed

Dery, Aurélie; Tran, Phuong Dat; Compère, Philippe; Dubois, Philippe

2018-07-01

When facing seawater undersaturated towards calcium carbonates, spines of classical sea urchins (euechinoids) show traces of corrosion although they are covered by an epidermis. Cidaroids (a sister clade of euechinoids) are provided with mature spines devoid of epidermis, which makes them, at first sight, more sensitive to dissolution when facing undersaturated seawater. A recent study showed that spines of a tropical cidaroid are resistant to dissolution due to the high density and the low magnesium concentration of the peculiar external spine layer, the cortex. The biofilm and epibionts covering the spines was also suggested to take part in the spine protection. Here, we investigate the protective role of these factors in different cidaroid species from a broad range of latitude, temperature and depth. The high density of the cortical layer and the cover of biofilm and epibionts were confirmed as key protection against dissolution. The low magnesium concentration of cidaroid spines compared to that of euechinoid ones makes them less soluble in general. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effects of Horizontal-Tail Location and Wing Modifications on the High-Speed Stability and Control Characteristics of a 01.17-Scale Model of the McDonnell XF2H-1 Airplane (TED No, NACA DE336)

NASA Technical Reports Server (NTRS)

Emerson, Horace F.; Axelson, John A.

1949-01-01

An additional series of high-speed wind-tunnel tests of a modified 0.17-scale model of the McDonnell XF2H-1 airplane was conducted to evaluate the effects of a reduction in the thickness-to-chord ratios of the tail planes, the displacement of the horizontal tail relative to the vertical tail, and the extension of the trailing edge of the wing. Two tail-intersection fairings designed to improve the flow at the tail were also tested. The pitching-moment characteristics of the model were improved slightly by the use of the thinner tail sections. Rearward or rearward and downward displacements of the horizontal tail increased the critical Mach number at the tail intersection from 0.725 to a maximum of 0.80, but caused an excessive change in pitching-moment coefficient at the higher Mach numbers. Extending the trailing edge of the wing did not improve the static longitudinal-stability characteristics, but increased the pitching-down tendency between 0.725 and 0.825 Mach numbers prior to the pitching-up tendency. The extended wing did, however, increase the Mach numbers at which these tendencies occurred. The increase in the Mach numbers of divergence and the tuft studies indicate a probable increase in the buffet limit of the prototype airplane. No perceptible improvement of flow at the tail intersection was observed with the two fairings tested on the forward tail configuration.

A nationwide epidemiological study of newly diagnosed spine metastasis in the adult Korean population.

PubMed

Sohn, Seil; Kim, Jinhee; Chung, Chun Kee; Lee, Na Rae; Park, Eunjung; Chang, Ung-Kyu; Sohn, Moon Jun; Kim, Sung Hwan

2016-08-01

Metastatic spine tumor has become clinically important because of the availability of improved diagnostic tools and increases in survival periods in cancer patients. In spite of this interest, the burden of metastatic spine tumor on the general population has not been extensively reported. The aim of this 2009-2011 nationwide study of adult Koreans was to describe characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. This is a retrospective cohort study. A national health insurance database was used to identify a cohort of patients with newly diagnosed metastatic spine tumors. This study aimed to analyze characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. Data for patients with metastatic spine tumors were extracted from the Korean Health Insurance Review and Assessment Service database. Data included patient age, sex, health insurance type, comorbidities, medical cost, and hospital stay duration. Hospital stay duration and medical costs per person during 1 calendar year were evaluated. In addition, survival rates of patients with metastatic spine tumor according to primary tumor sites were evaluated. The incidence rate of spine metastasis increased with age, year of diagnosis, and the number of comorbidities (p≤.0001). The 6 most prevalent primary tumor sites were lung, liver and biliary tract, breast, colon, stomach, and prostate. Of patients with the 6 most prevalent primary tumors, total average annual medical costs, including inpatient and outpatient services, ranged from 12,734USD (prostate origin) to 15,556 USD (lung origin). Of patients with the 6 most prevalent primary tumors, total average annual hospital stay duration, including inpatient and outpatient services, ranged from 70.8 days (stomach origin) to 78.7 days (colon origin). Median overall survival duration in patients with

Evaluating the Relationship Between Muscle Activation and Spine Kinematics Through Wavelet Coherence.

PubMed

Hay, Dean C; Wachowiak, Mark P; Graham, Ryan B

2016-10-01

Advances in time-frequency analysis can provide new insights into the important, yet complex relationship between muscle activation (ie, electromyography [EMG]) and motion during dynamic tasks. We use wavelet coherence to compare a fundamental cyclical movement (lumbar spine flexion and extension) to the surface EMG linear envelope of 2 trunk muscles (lumbar erector spinae and internal oblique). Both muscles cohere to the spine kinematics at the main cyclic frequency, but lumbar erector spinae exhibits significantly greater coherence than internal oblique to kinematics at 0.25, 0.5, and 1.0 Hz. Coherence phase plots of the 2 muscles exhibit different characteristics. The lumbar erector spinae precedes trunk extension at 0.25 Hz, whereas internal oblique is in phase with spine kinematics. These differences may be due to their proposed contrasting functions as a primary spine mover (lumbar erector spinae) versus a spine stabilizer (internal oblique). We believe that this method will be useful in evaluating how a variety of factors (eg, pain, dysfunction, pathology, fatigue) affect the relationship between muscles' motor inputs (ie, activation measured using EMG) and outputs (ie, the resulting joint motion patterns).

Male and Female Cervical Spine Biomechanics and Anatomy: Implication for Scaling Injury Criteria.

PubMed

Yoganandan, Narayan; Bass, Cameron R; Voo, Liming; Pintar, Frank A

2017-05-01

There is an increased need to develop female-specific injury criteria and anthropomorphic test devices (dummies) for military and automotive environments, especially as women take occupational roles traditionally reserved for men. Although some exhaustive reviews on the biomechanics and injuries of the human spine have appeared in clinical and bioengineering literatures, focus has been largely ignored on the difference between male and female cervical spine responses and characteristics. Current neck injury criteria for automotive dummies for assessing crashworthiness and occupant safety are obtained from animal and human cadaver experiments, computational modeling, and human volunteer studies. They are also used in the military. Since the average human female spines are smaller than average male spines, metrics specific to the female population may be derived using simple geometric scaling, based on the assumption that male and female spines are geometrically scalable. However, as described in this technical brief, studies have shown that the biomechanical responses between males and females do not obey strict geometric similitude. Anatomical differences in terms of the structural component geometry are also different between the two cervical spines. Postural, physiological, and motion responses under automotive scenarios are also different. This technical brief, focused on such nonuniform differences, underscores the need to conduct female spine-specific evaluations/experiments to derive injury criteria for this important group of the population.

Research articles published by Korean spine surgeons: Scientific progress and the increase in spine surgery.

PubMed

Lee, Soo Eon; Jahng, Tae-Ahn; Kim, Ki-Jeong; Hyun, Seung-Jae; Kim, Hyun Jib; Kawaguchi, Yoshiharu

2017-02-01

There has been a marked increase in spine surgery in the 21st century, but there are no reports providing quantitative and qualitative analyses of research by Korean spine surgeons. The study goal was to assess the status of Korean spinal surgery and research. The number of spine surgeries was obtained from the Korean National Health Insurance Service. Research articles published by Korean spine surgeons were reviewed by using the Medline/PubMed online database. The number of spine surgeries in Korea increased markedly from 92,390 in 2004 to 164,291 in 2013. During the 2000-2014 period, 1982 articles were published by Korean spine surgeons. The annual number of articles increased from 20 articles in 2000 to 293 articles in 2014. There was a positive correlation between the annual spine surgery and article numbers (p<0.001). There were 1176 original studies published, and there was an annual increase in articles with Oxford levels of evidence 1, 2, and 3. The mean five-year impact factor (IF) for article quality was 1.79. There was no positive correlation between the annual IF and article numbers. Most articles (65.9%) were authored by neurosurgical spine surgeons. But spinal deformity-related topics were dominant among articles authored by orthopedics. The results show a clear quantitative increase in Korean spinal surgery and research over the last 15years. The lack of a correlation between annual IF and published article numbers indicate that Korean spine surgeons should endeavor to increase research value. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ratfish (Chimaera) spine injuries in fishermen.

PubMed

Hayes, A J; Sim, A J W

2011-08-01

An occupational hazard peculiar to fishermen, is an injury from a sharp fish spine. Such spines can cause envenomation injury, infectious sequelae or trauma to anatomical structures. The management of two fishermen with penetrating ratfish (Chimaera) spine injuries to the lower limb is described. Both were managed by removal of the spine under general anaesthesia. In the second patient, the spine was embedded adjacent to the left femoral artery, highlighting the potential for major haemorrhage and supporting the use of surgical wound exploration when important structures may be involved. Herein, we describe the first report in English of Chimaera spine injury. In addition, we surveyed nine northeast Atlantic deep-sea fishermen to gain information on exposure to, and injuries from, this type of fish. The most commonly identified species was Chimaera monstrosa. Five fishermen reported injuries to their feet or hands from Chimaera spines and two had sought medical attention. The evidence indicates that deep-sea trawler fishermen of the northeast Atlantic frequently encounter Chimaera species and can suffer dangerous penetrating wounds from its dorsal spine.

Numerical analysis of band tails in nanowires and their effects on the performance of tunneling field-effect transistors

NASA Astrophysics Data System (ADS)

Tanaka, Takahisa; Uchida, Ken

2018-06-01

Band tails in heavily doped semiconductors are one of the important parameters that determine transfer characteristics of tunneling field-effect transistors. In this study, doping concentration and doing profile dependences of band tails in heavily doped Si nanowires were analyzed by a nonequilibrium Green function method. From the calculated band tails, transfer characteristics of nanowire tunnel field-effect transistors were numerically analyzed by Wentzel–Kramer–Brillouin approximation with exponential barriers. The calculated transfer characteristics demonstrate that the band tails induced by dopants degrade the subthreshold slopes of Si nanowires from 5 to 56 mV/dec in the worst case. On the other hand, surface doping leads to a high drain current while maintaining a small subthreshold slope.

The effects of radiation therapy on height and spine MRI characteristics in children with neuroblastoma.

PubMed

Yu, Jeong Il; Lim, Do Hoon; Jung, Sang Hoon; Sung, Ki Woong; Yoo, So-Young; Nam, Heerim

2015-03-01

To investigate the effect of radiotherapy (RT) on height and spine using magnetic resonance imaging (MRI) analysis in children with neuroblastoma and to identify parameters related to patient height. We performed a retrospective cohort study of neuroblastoma patients treated between January 1997 and December 2007. Twenty-seven children were enrolled. Whole spine MRI was completed and height percentiles were compared with national growth charts. The median ages were 28, 43, and 126 months at diagnosis, RT, and analysis, respectively. All of the enrolled children received local RT, and 15 patients received total body irradiation (TBI). Median growth percentiles were 67.0, 54.0, and 4.9 at diagnosis, RT, and analysis, respectively. The number of irradiated vertebrae (P=0.009) and having undergone TBI (P=0.03) were significantly associated with shorter stature. Among the MRI parameters for irradiated vertebrae, signal intensity was higher (P=0.05) and more heterogeneous (P=0.02) in T1-weighted images and roundness was lower (P=0.03) in T2-weighted images. Height of children with neuroblastoma was significantly affected by RT. The number of irradiated vertebrae and having undergone TBI were significantly associated with lower height. Irradiated spine showed changes in both signal and shape on MRI. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Tail gut cyst.

PubMed

Rao, G Mallikarjuna; Haricharan, P; Ramanujacharyulu, S; Reddy, K Lakshmi

2002-01-01

The tail gut is a blind extension of the hindgut into the tail fold just distal to the cloacal membrane. Remnants of this structure may form tail gut cyst. We report a 14-year-old girl with tail gut cyst that presented as acute abdomen. The patient recovered after cyst excision.

Telling tails: selective pressures acting on investment in lizard tails.

PubMed

Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

2013-01-01

Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P < 0.001; also significant for five of the six families tested separately), as do longer (all species, P < 0.001; Iguanidae, P < 0.05; Lacertidae, P < 0.001; Scindidae, P < 0.001), climbing (all species, P < 0.05), and diurnal (all species, P < 0.01; Pygopodidae, P < 0.01) species; geckos without specialized tails (P < 0.05); or active-foraging skinks (P < 0.05). We also found some relationships with the data for caudal autotomy, with more lost/regenerating tails for nocturnal lizards (all 246 spp., P < 0.01; Scindidae, P < 0.05), larger skinks (P < 0.05), climbing geckos (P < 0

Plasma currents and anisotropy in the tail-dipole transition region

NASA Astrophysics Data System (ADS)

Artemyev, A.; Zhang, X. J.; Angelopoulos, V.; Runov, A.

2017-12-01

Using conjugated THEMIS and Van Allen Probes observations in the nightside magnetosphere, we examine statistically plasma and magnetic field characteristics at multiple locations simultaneously across the 3-10 RE region (i.e., across the tail-dipole transition region, whose location depends on tail flux loading and the strength of global convection). We find that the spatial distributions of ion and electron anisotropies vary significantly but systematically with radial distance and geomagnetic activity. For low Kp (<2), ions are transversely anisotropic near Earth but isotropic in the tail, whereas electrons are isotropic closer to Earth but field-aligned in tail. For large Kp (>4), the anisotropy profiles for ions and electrons reverse: ions are isotropic closer to the Earth and field-aligned in the tail, whereas electrons are transversely anisotropic closer to Earth but isotropic in the tail. Using the measured plasma anisotropy radial profiles we estimate the currents from curvature drifts and compare them with diamagnetic currents. We also discuss the implications of the observed plasma anisotropies for the presence and spatial distribution of field-aligned electric fields.

The Neandertal vertebral column 1: the cervical spine.

PubMed

Gómez-Olivencia, Asier; Been, Ella; Arsuaga, Juan Luis; Stock, Jay T

2013-06-01

This paper provides a metric analysis of the Neandertal cervical spine in relation to modern human variation. All seven cervical vertebrae have been analysed. Metric data from eight Neandertal individuals are compared with a large sample of modern humans. The significance of morphometric differences is tested using both z-scores and two-tailed Wilcoxon signed rank tests. The results identify significant metric and morphological differences between Neandertals and modern humans in all seven cervical vertebrae. Neandertal vertebrae are mediolaterally wider and dorsoventrally longer than modern humans, due in part to longer and more horizontally oriented spinous processes. This suggests that Neandertal cervical morphology was more stable in both mid-sagittal and coronal planes. It is hypothesized that the differences in cranial size and shape in the Neandertal and modern human lineages from their Middle Pleistocene ancestors could account for some of the differences in the neck anatomy between these species. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dendritic Spine Pathology in Schizophrenia

PubMed Central

Glausier, Jill R.; Lewis, David A.

2012-01-01

Schizophrenia is a neurodevelopmental disorder whose clinical features include impairments in perception, cognition and motivation. These impairments reflect alterations in neuronal circuitry within and across multiple brain regions that are due, at least in part, to deficits in dendritic spines, the site of most excitatory synaptic connections. Dendritic spine alterations have been identified in multiple brain regions in schizophrenia, but are best characterized in layer 3 of the neocortex, where pyramidal cell spine density is lower. These spine deficits appear to arise during development, and thus are likely the result of disturbances in the molecular mechanisms that underlie spine formation, pruning, and/or maintenance. Each of these mechanisms may provide insight into novel therapeutic targets for preventing or repairing the alterations in neural circuitry that mediate the debilitating symptoms of schizophrenia. PMID:22546337

Micromechanics of Sea Urchin spines.

PubMed

Tsafnat, Naomi; Fitz Gerald, John D; Le, Hai N; Stachurski, Zbigniew H

2012-01-01

The endoskeletal structure of the Sea Urchin, Centrostephanus rodgersii, has numerous long spines whose known functions include locomotion, sensing, and protection against predators. These spines have a remarkable internal microstructure and are made of single-crystal calcite. A finite-element model of the spine's unique porous structure, based on micro-computed tomography (microCT) and incorporating anisotropic material properties, was developed to study its response to mechanical loading. Simulations show that high stress concentrations occur at certain points in the spine's architecture; brittle cracking would likely initiate in these regions. These analyses demonstrate that the organization of single-crystal calcite in the unique, intricate morphology of the sea urchin spine results in a strong, stiff and lightweight structure that enhances its strength despite the brittleness of its constituent material.

Dendritic spines linearize the summation of excitatory potentials

PubMed Central

Araya, Roberto; Eisenthal, Kenneth B.; Yuste, Rafael

2006-01-01

In mammalian cortex, most excitatory inputs occur on dendritic spines, avoiding dendritic shafts. Although spines biochemically isolate inputs, nonspiny neurons can also implement biochemical compartmentalization; so, it is possible that spines have an additional function. We have recently shown that the spine neck can filter membrane potentials going into and out of the spine. To investigate the potential function of this electrical filtering, we used two-photon uncaging of glutamate and compared the integration of electrical signals in spines vs. dendritic shafts from basal dendrites of mouse layer 5 pyramidal neurons. Uncaging potentials onto spines summed linearly, whereas potentials on dendritic shafts reduced each other's effect. Linear integration of spines was maintained regardless of the amplitude of the response, distance between spines (as close as <2 μm), distance of the spines to the soma, dendritic diameter, or spine neck length. Our findings indicate that spines serve as electrical isolators to prevent input interaction, and thus generate a linear arithmetic of excitatory inputs. Linear integration could be an essential feature of cortical and other spine-laden circuits. PMID:17132736

Dendritic spines linearize the summation of excitatory potentials.

PubMed

Araya, Roberto; Eisenthal, Kenneth B; Yuste, Rafael

2006-12-05

In mammalian cortex, most excitatory inputs occur on dendritic spines, avoiding dendritic shafts. Although spines biochemically isolate inputs, nonspiny neurons can also implement biochemical compartmentalization; so, it is possible that spines have an additional function. We have recently shown that the spine neck can filter membrane potentials going into and out of the spine. To investigate the potential function of this electrical filtering, we used two-photon uncaging of glutamate and compared the integration of electrical signals in spines vs. dendritic shafts from basal dendrites of mouse layer 5 pyramidal neurons. Uncaging potentials onto spines summed linearly, whereas potentials on dendritic shafts reduced each other's effect. Linear integration of spines was maintained regardless of the amplitude of the response, distance between spines (as close as < 2 microm), distance of the spines to the soma, dendritic diameter, or spine neck length. Our findings indicate that spines serve as electrical isolators to prevent input interaction, and thus generate a linear arithmetic of excitatory inputs. Linear integration could be an essential feature of cortical and other spine-laden circuits.

Cervical Spine Injuries in the Athlete.

PubMed

Schroeder, Gregory D; Vaccaro, Alexander R

2016-09-01

Cervical spine injuries are extremely common and range from relatively minor injuries, such as cervical muscle strains, to severe, life-threatening cervical fractures with spinal cord injuries. Although cervical spine injuries are most common in athletes who participate in contact and collision sports, such as American football and rugby, they also have been reported in athletes who participate in noncontact sports, such as baseball, gymnastics, and diving. Cervical spine injuries in athletes are not necessarily the result of substantial spine trauma; some athletes have chronic conditions, such as congenital stenosis, that increase their risk for a serious cervical spine injury after even minor trauma. Therefore, physicians who cover athletic events must have a thorough knowledge of cervical spine injures and the most appropriate ways in which they should be managed. Although cervical spine injuries can be career-ending injuries, athletes often are able to return to play after appropriate treatment if the potential for substantial re-injury is minimized.

Effect of nose shape and tail length on supersonic stability characteristics of a projectile

NASA Technical Reports Server (NTRS)

Sawyer, W. C.; Collins, I. K.

1973-01-01

The effect of nose shape and tail length on the static stability of a fin-stabilized projectile has been investigated in the Langley Unitary Plan with tunnel at angles of attack to about 12 deg for a Mach number range from 1.5 to 2.5. The tests were made at a constant Reynolds number of 6.56 x 1,000,000 per meter. The results of the investigation showed that nose shape had no effect on the static stability. Increasing the tail length resulted in a progressively stabilizing tendency. However, only the 1.5-caliber-tail-length configuration was stable over the test angle-of-attack range at Mach number 1.5. This configuration was marginally stable or unstable at the higher Mach numbers, and the shorter configurations were unstable at all Mach numbers for either part of or the entire test angle-of-attack range.

Functional anatomy of the spine.

PubMed

Bogduk, Nikolai

2016-01-01

Among other important features of the functional anatomy of the spine, described in this chapter, is the remarkable difference between the design and function of the cervical spine and that of the lumbar spine. In the cervical spine, the atlas serves to transmit the load of the head to the typical cervical vertebrae. The axis adapts the suboccipital region to the typical cervical spine. In cervical intervertebrtal discs the anulus fibrosus is not circumferential but is crescentic, and serves as an interosseous ligament in the saddle joint between vertebral bodies. Cervical vertebrae rotate and translate in the sagittal plane, and rotate in the manner of an inverted cone, across an oblique coronal plane. The cervical zygapophysial joints are the most common source of chronic neck pain. By contrast, lumbar discs are well designed to sustain compression loads, but rely on posterior elements to limit axial rotation. Internal disc disruption is the most common basis for chronic low-back pain. Spinal muscles are arranged systematically in prevertebral and postvertebral groups. The intrinsic elements of the spine are innervated by the dorsal rami of the spinal nerves, and by the sinuvertebral nerves. Little modern research has been conducted into the structure of the thoracic spine, or the causes of thoracic spinal pain. © 2016 Elsevier B.V. All rights reserved.

Relevant Anatomic and Morphological Measurements of the Rat Spine: Considerations for Rodent Models of Human Spine Trauma.

PubMed

Jaumard, Nicolas V; Leung, Jennifer; Gokhale, Akhilesh J; Guarino, Benjamin B; Welch, William C; Winkelstein, Beth A

2015-10-15

Basic science study measuring anatomical features of the cervical and lumbar spine in rat with normalized comparison with the human. The goal of this study is to comprehensively compare the rat and human cervical and lumbar spines to investigate whether the rat is an appropriate model for spine biomechanics investigations. Animal models have been used for a long time to investigate the effects of trauma, degenerative changes, and mechanical loading on the structure and function of the spine. Comparative studies have reported some mechanical properties and/or anatomical dimensions of the spine to be similar between various species. However, those studies are largely limited to the lumbar spine, and a comprehensive comparison of the rat and human spines is lacking. Spines were harvested from male Holtzman rats (n = 5) and were scanned using micro- computed tomography and digitally rendered in 3 dimensions to quantify the spinal bony anatomy, including the lateral width and anteroposterior depth of the vertebra, vertebral body, and spinal canal, as well as the vertebral body and intervertebral disc heights. Normalized measurements of the vertebra, vertebral body, and spinal canal of the rat were computed and compared with corresponding measurements from the literature for the human in the cervical and lumbar spinal regions. The vertebral dimensions of the rat spine vary more between spinal levels than in humans. Rat vertebrae are more slender than human vertebrae, but the width-to-depth axial aspect ratios are very similar in both species in both the cervical and lumbar regions, especially for the spinal canal. The similar spinal morphology in the axial plane between rats and humans supports using the rat spine as an appropriate surrogate for modeling axial and shear loading of the human spine.

[Injuries of the cervical spine in motorcycling and bicycling traffic accidents].

PubMed

Jecmenica, D S; Alempijević, Dj M; Aleksandrić, B V; Pavlekić, S B; Baralić, I; Antić, B Z

2010-01-01

Due to the vehicle characteristics neck injuries are common in motorcycle and moped users involved in traffic accidents. We are reporting on neck injuries amongst 502 fatalities of drivers and passengers of motorcycles and mopeds, and cyclists. Cervical spine injuries were found in 124 cases (24.7%). Cervical spine injury was statistically significantly more frequently in passengers (61.9%) compared to the drivers (20.7%) of motorcycle and moped (chi2 = 13.384; p < 0.01), the lesions are usually localized in the upper cervical spine (52.4%), the most frequently at atlantoocciptal region (F = 25.835; p); these injuries were most frequently caused by frontal (31.45%) or rear (50.81%) axial collisions. Almost all cases of cervical spine injuries were present without apparent external injuries; they were associated with lesions of neck muscles, blood vessels and/or neck organs, and in 79 cases (63.7%) there was a lesion of the cervical spinal cord. The research results indicate a large incidence of neck injuries in traffic accidents especially in motorcycle, moped and bicycle axial collision with the possible absence of external injuries, which may represent a clinical and forensic problem.

Subsonic and supersonic longitudinal stability and control characteristics of an aft tail fighter configuration with cambered and uncambered wings and uncambered fuselage

NASA Technical Reports Server (NTRS)

Dollyhigh, S. M.

1974-01-01

An investigation has been made in the Mach number range from 0.20 to 2.16 to determine the longitudinal aerodynamic characteristics of a fighter airplane concept. The configuration concept employs a single fixed geometry inlet, a 50 deg leading-edge-angle clipped-arrow wing, a single large vertical tail, and low horizontal tails. The wing camber surface was optimized in drag due to lift and was designed to be self-trimming at Mach 1.40 and at a lift coefficient of 0.20. An uncambered or flat wing of the same planform and thickness ratio was also tested. However, for the present investigation, the fuselage was not cambered. Further tests should be made on a cambered fuselage version, which attempts to preserve the optimum wing loading on that part of the theoretical wing enclosed by the fuselage.

Lumbosacral spine x-ray

MedlinePlus

X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray ...

Spatial Characteristics of F/A-18 Vertical Tail Buffet Pressures Measured in Flight

NASA Technical Reports Server (NTRS)

Moses, Robert W.; Shah, Gautam H.

1998-01-01

Buffeting is an aeroelastic phenomenon which plagues high performance aircraft, especially those with twin vertical tails, at high angles of attack. Previous wind-tunnel and flight tests were conducted to characterize the buffet loads on the vertical tails by measuring surface pressures, bending moments, and accelerations. Following these tests, buffeting estimates were computed using the measured buffet pressures and compared to the measured responses. The estimates did not match the measured data because the assumed spatial correlation of the buffet pressures was not correct. A better understanding of the partial (spatial) correlation of the differential buffet pressures on the tail was necessary to improve the buffeting estimates. Several wind-tunnel investigations were conducted for this purpose. When combined and compared, the results of these tests show that the partial correlation depends on and scales with flight conditions. One of the remaining questions is whether the windtunnel data is consistent with flight data. Presented herein, cross-spectra and coherence functions calculated from pressures that were measured on the high alpha research vehicle (HARV) indicate that the partial correlation of the buffet pressures in flight agrees with the partial correlation observed in the wind tunnel.

Study on immobilization and migration of nuclide u in superficial soil of uranium tailings pond

NASA Astrophysics Data System (ADS)

Chang, Zhe; Zhou, Shukui

2017-05-01

The uranium tailings in southern China was used as the object of study to study the fixation and migration characteristics of nuclide U in shallow tailings. The results showed that the precipitation of tailings in the tailings soil was not linearly related to the depth during the acid rain leaching process. Tailings soil in the role of fixatives, when the lime as a fixative, the tailings of different soil uranium in 20 days after the re-precipitation. However, when lime and ammonium phosphate were used as fixing agents, the cumulative precipitation of U had a significant effect, and the migration of uranium was inhibited.

Maxillofacial trauma - Underestimation of cervical spine injury.

PubMed

Reich, Waldemar; Surov, Alexey; Eckert, Alexander Walter

2016-09-01

Undiagnosed cervical spine injury can have devastating results. The aim of this study was to analyse patients with primary maxillofacial trauma and a concomitant cervical spine injury. It is hypothetised that cervical spine injury is predictable in maxillofacial surgery. A monocentric clinical study was conducted over a 10-year period to analyse patients with primary maxillofacial and associated cervical spine injuries. Demographic data, mechanism of injury, specific trauma and treatments provided were reviewed. Additionally a search of relevant international literature was conducted in PubMed by terms "maxillofacial" AND "cervical spine" AND "injury". Of 3956 patients, n = 3732 (94.3%) suffered from craniomaxillofacial injuries only, n = 174 (4.4%) from cervical spine injuries only, and n = 50 (1.3%) from both craniomaxillofacial and cervical spine injuries. In this study cohort the most prevalent craniofacial injuries were: n = 41 (44%) midfacial and n = 21 (22.6%) skull base fractures. Cervical spine injuries primarily affected the upper cervical spine column: n = 39 (58.2%) vs. n = 28 (41.8%). Only in 3 of 50 cases (6%), the cervical spine injury was diagnosed coincidentally, and the cervical spine column was under immobilised. The operative treatment rate for maxillofacial injuries was 36% (n = 18), and for cervical spine injuries 20% (n = 10). The overall mortality rate was 8% (n = 4). The literature search yielded only 12 papers (11 retrospective and monocentric cohort studies) and is discussed before our own results. In cases of apparently isolated maxillofacial trauma, maxillofacial surgeons should be aware of a low but serious risk of underestimating an unstable cervical spine injury. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Gunshot wounds to the spine in post-Katrina New Orleans.

PubMed

Trahan, Jayme; Serban, Daniel; Tender, Gabriel C

2013-11-01

Gunshot wounds (GSW) to the spine represent a major health concern within today's society. Our study assessed the epidemiologic characteristics of patients with GSW to the spine treated in New Orleans. A retrospective chart review was performed from January 2007 through November 2011 on all the patients who were seen in the emergency room and diagnosed with a gunshot wound to the spine. Epidemiologic factors, as well as the results of admission toxicology screening, were noted. Outcome analysis was performed on patients undergoing conservative versus operative management for their injuries. Clinical outcomes were assessed using the ASIA classification system. Complications related to initial injury, neurosurgical procedures, and hospital stay were noted. A total of 147 patients were enrolled. Of those diagnosed with a GSW to the spine, 88 (59.8%) received an admission toxicology screen. Seventy-three (83%) patients out of those tested had a positive screen, with the most common substances detected being cannabis, cocaine, and alcohol. In regards to management, 127 (87%) patients were treated conservatively and only one (0.7%) patient improved clinically from ASIA D to E. Of the 20 patients who underwent surgery, one (5%) patient had clinical improvement post-operatively from ASIA C to D. This study evaluates the largest number of patients with GSW to the spine per year treated in a single centre, illustrating the violent nature of New Orleans. In this urban population, there was a clear correlation between drug use and suffering a GSW to the spine. Surgical intervention was seldom indicated in these patients and was predominately used for fixation of unstable fractures and decompression of compressive injuries, particularly below T11. Minimally invasive techniques were used successfully at our institution to minimize the risk of post-operative CSF leak. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Cervical spine instability in the surgical patient].

PubMed

Barbeito, A; Guerri-Guttenberg, R A

2014-03-01

Many congenital and acquired diseases, including trauma, may result in cervical spine instability. Given that airway management is closely related to the movement of the cervical spine, it is important that the anesthesiologist has detailed knowledge of the anatomy, the mechanisms of cervical spine instability, and of the effects that the different airway maneuvers have on the cervical spine. We first review the normal anatomy and biomechanics of the cervical spine in the context of airway management and the concept of cervical spine instability. In the second part, we review the protocols for the management of cervical spine instability in trauma victims and some of the airway management options for these patients. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. All rights reserved.

Measurement And Shape Analysis Including Vertebral Rotation Of Scoliotic Spines From Single Plane Radiographs

NASA Astrophysics Data System (ADS)

Drerup, B.; Hierholzer, E.

1986-07-01

Radiological assessment and follow-up control of scoliosis, i.e. of a lateral and rotational deviation of the spine, is performed mainly by single plane radiographs. Additional information may be gained from these radiographs by introducing a parametrized vertebral model. By analyzing the radiographic contours according to this model, axial rotation can be determined for any position and orientation of the vertebra. In addition to rotation several other data are determined for each vertebra, such as the tilting angle and the two-dimensional coordinates of the centre. By handling the data as a function of the vertebral location in spine, characteristic curves are generated. In order to find simple shape parameters for these characteristics, a smooth curve has to be fitted to the data points by a least squares approximation. This problem may be solved by a Fourier decomposition of the spinal curves. It appears, that the Fourier coefficients (amplitudes and phases) and some derived shape parameters lend themselves to a medical interpretation, which is consistent with the existing classification of the scoliotic spine.

Predicting medical complications after spine surgery: a validated model using a prospective surgical registry.

PubMed

Lee, Michael J; Cizik, Amy M; Hamilton, Deven; Chapman, Jens R

2014-02-01

The possibility and likelihood of a postoperative medical complication after spine surgery undoubtedly play a major role in the decision making of the surgeon and patient alike. Although prior study has determined relative risk and odds ratio values to quantify risk factors, these values may be difficult to translate to the patient during counseling of surgical options. Ideally, a model that predicts absolute risk of medical complication, rather than relative risk or odds ratio values, would greatly enhance the discussion of safety of spine surgery. To date, there is no risk stratification model that specifically predicts the risk of medical complication. The purpose of this study was to create and validate a predictive model for the risk of medical complication during and after spine surgery. Statistical analysis using a prospective surgical spine registry that recorded extensive demographic, surgical, and complication data. Outcomes examined are medical complications that were specifically defined a priori. This analysis is a continuation of statistical analysis of our previously published report. Using a prospectively collected surgical registry of more than 1,476 patients with extensive demographic, comorbidity, surgical, and complication detail recorded for 2 years after surgery, we previously identified several risk factor for medical complications. Using the beta coefficients from those log binomial regression analyses, we created a model to predict the occurrence of medical complication after spine surgery. We split our data into two subsets for internal and cross-validation of our model. We created two predictive models: one predicting the occurrence of any medical complication and the other predicting the occurrence of a major medical complication. The final predictive model for any medical complications had a receiver operator curve characteristic of 0.76, considered to be a fair measure. The final predictive model for any major medical complications had

Characteristics of white-tailed deer fawn beds, Black Hills, South Dakota

Treesearch

Daniel W. Uresk; Ted A. Benzon; Kieth E. Severson; Lakhdar Benkobi

1999-01-01

Forty-two white-tailed deer fawns (Odocoileus virginianus dakotensis) were captured and fitted with radio transmitters and observed from June through September 1991 and 1992 to determine diurnal bed site use in the Black Hills of South Dakota. Fawns were monitored biweekly during daylight hours and 259 bed sites were located. In addition, 301 random...

Heritability of Thoracic Spine Curvature and Genetic Correlations With Other Spine Traits: The Framingham Study

PubMed Central

Yau, Michelle S; Demissie, Serkalem; Zhou, Yanhua; Anderson, Dennis E; Lorbergs, Amanda L; Kiel, Douglas P; Allaire, Brett T; Yang, Laiji; Cupples, L Adrienne; Travison, Thomas G; Bouxsein, Mary L; Karasik, David; Samelson, Elizabeth J

2017-01-01

Hyperkyphosis is a common spinal disorder in older adults, characterized by excessive forward curvature of the thoracic spine and adverse health outcomes. The etiology of hyperkyphosis has not been firmly established, but may be related to changes that occur with aging in the vertebrae, discs, joints, and muscles, which function as a unit to support the spine. Determining the contribution of genetics to thoracic spine curvature and the degree of genetic sharing among co-occurring measures of spine health may provide insight into the etiology of hyperkyphosis. The purpose of our study was to estimate heritability of thoracic spine curvature using T4–T12 kyphosis (Cobb) angle and genetic correlations between thoracic spine curvature and vertebral fracture, intervertebral disc height narrowing, facet joint osteoarthritis (OA), lumbar spine volumetric bone mineral density (vBMD), and paraspinal muscle area and density, which were all assessed from computed tomography (CT) images. Participants included 2063 women and men in the second and third generation offspring of the original cohort of the Framingham Study. Heritability of kyphosis angle, adjusted for age, sex, and weight, was 54% (95% confidence interval [CI], 43% to 64%). We found moderate genetic correlations between kyphosis angle and paraspinal muscle area ( ρ^G, −0.46; 95% CI, −0.67 to −0.26), vertebral fracture ( ρ^G, 0.39; 95% CI, 0.18 to 0.61), vBMD ( ρ^G,−0.23; 95% CI, −0.41 to −0.04), and paraspinal muscle density ( ρ^G,−0.22; 95% CI, −0.48 to 0.03). Genetic correlations between kyphosis angle and disc height narrowing ( ρ^G, 0.17; 95% CI, −0.05 to 0.38) and facet joint OA ( ρ^G, 0.05; 95% CI, −0.15 to 0.24) were low. Thoracic spine curvature may be heritable and share genetic factors with other age-related spine traits including trunk muscle size, vertebral fracture, and bone mineral density. PMID:27455046

Mine tailings composition in a historic site: implications for ecological restoration.

PubMed

Courtney, R

2013-02-01

Ecological restoration, using tolerant plant species and nutrient additions, is a low-cost option to decrease environmental risks associated with mine tailings. An attempt was previously made to establish such a vegetation cover on an abandoned tailings facility in Southern Ireland. Historically, the tailings site has been prone to dusting and is a potential source of contamination to the surrounding environment. The site was examined to determine the success of the previous restoration plan used to revegetate the site and to determine its suitability for further restoration. Three distinct floristic areas were identified (grassland, poor grassland and bare area) based on herbage compositions and elemental analysis. Surface and subsurface samples were taken to characterise tailings from within these areas of the tailings site. The pH of bare surface tailings (pH, 2.7) was significantly more acidic (p < 0.5) than in other areas. Additionally, negligible net neutralising potential resulted in the tailings being hostile to plant growth. Total metal concentrations in tailings were high (c. 10,000 mg kg(-1) for Pb and up to 20,000 mg kg(-1) for Zn). DTPA-extractable Zn and Pb were 16 and 11 % of the total amount, respectively. Metal content in grasses growing on some areas of the tailings were elevated and demonstrated the inability of the tailings to support sustainable plant growth. Due to the inherently hostile characteristics of these areas, future restoration work will employ capping with a barrier layer.

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

Aquatic antagonists: cutaneous sea urchin spine injury.

PubMed

Hsieh, Clifford; Aronson, Erica R; Ruiz de Luzuriaga, Arlene M

2016-11-01

Injuries from sea urchin spines are commonly seen in coastal regions with high levels of participation in water activities. Although these injuries may seem minor, the consequences vary based on the location of the injury. Sea urchin spine injuries may cause arthritis and synovitis from spines in the joints. Nonjoint injuries have been reported, and dermatologic aspects of sea urchin spine injuries rarely have been discussed. We present a case of a patient with sea urchin spines embedded in the thigh who subsequently developed painful skin nodules. Tissue from the site of the injury demonstrated foreign-body type granulomas. Following the removal of the spines and granulomatous tissue, the patient experienced resolution of the nodules and associated pain. Extraction of sea urchin spines can attenuate the pain and decrease the likelihood of granuloma formation, infection, and long-term sequelae.

Optimal heavy tail estimation - Part 1: Order selection

NASA Astrophysics Data System (ADS)

Mudelsee, Manfred; Bermejo, Miguel A.

2017-12-01

The tail probability, P, of the distribution of a variable is important for risk analysis of extremes. Many variables in complex geophysical systems show heavy tails, where P decreases with the value, x, of a variable as a power law with a characteristic exponent, α. Accurate estimation of α on the basis of data is currently hindered by the problem of the selection of the order, that is, the number of largest x values to utilize for the estimation. This paper presents a new, widely applicable, data-adaptive order selector, which is based on computer simulations and brute force search. It is the first in a set of papers on optimal heavy tail estimation. The new selector outperforms competitors in a Monte Carlo experiment, where simulated data are generated from stable distributions and AR(1) serial dependence. We calculate error bars for the estimated α by means of simulations. We illustrate the method on an artificial time series. We apply it to an observed, hydrological time series from the River Elbe and find an estimated characteristic exponent of 1.48 ± 0.13. This result indicates finite mean but infinite variance of the statistical distribution of river runoff.

The importance of preoperative tissue sampling for mobile spine chordomas: literature review and report of two cases.

PubMed

Zuccato, Jeffrey A; Witiw, Christopher D; Keith, Julia; Dyer, Erin; Saghal, Arjun; da Costa, Leodante

2018-01-01

Pre-operative biopsy and diagnosis of chordomas of the mobile spine is indicated as en bloc resections improve outcomes. This review of the management of mobile spine chordomas includes two cases of unexpected mobile spine chordomas where a preoperative tissue diagnosis was decided against and may have altered surgical decision-making. Two lumbar spine chordomas thought to be metastatic and primary bony lesions preoperatively were not biopsied before surgery and eventual pathology revealed chordoma. Preoperative diagnoses were questioned during surgery after an intraoperative tissue diagnosis of chordoma in one case and unclear pathology with non-characteristic tumor morphology in the other. The surgical plan was altered in these cases to maximize resection as en bloc resection reduces the risk of local recurrence in chordoma. Mobile spine chordomas are rare and en bloc resection is recommended, contrary to the usual approach to more common spine tumors. Since en bloc resection of spine chordomas improves disease free survival, it has been recommended that tissue diagnosis be obtained preoperatively when chordoma is considered in the differential diagnosis, in order to guide surgical planning. We present two cases where a preoperative biopsy was considered but not obtained after neuroradiology consultation and imaging review, which may have been managed differently if the diagnosis of spine chordomas were known pre-operatively.

Diagnostic imaging of solitary tumors of the spine: what to do and say.

PubMed

Rodallec, Mathieu H; Feydy, Antoine; Larousserie, Frédérique; Anract, Philippe; Campagna, Raphaël; Babinet, Antoine; Zins, Marc; Drapé, Jean-Luc

2008-01-01

Metastatic disease, myeloma, and lymphoma are the most common malignant spinal tumors. Hemangioma is the most common benign tumor of the spine. Other primary osseous lesions of the spine are more unusual but may exhibit characteristic imaging features that can help the radiologist develop a differential diagnosis. Radiologic evaluation of a patient who presents with osseous vertebral lesions often includes radiography, computed tomography (CT), and magnetic resonance (MR) imaging. Because of the complex anatomy of the vertebrae, CT is more useful than conventional radiography for evaluating lesion location and analyzing bone destruction and condensation. The diagnosis of spinal tumors is based on patient age, topographic features of the tumor, and lesion pattern as seen at CT and MR imaging. A systematic approach is useful for recognizing tumors of the spine with characteristic features such as bone island, osteoid osteoma, osteochondroma, chondrosarcoma, vertebral angioma, and aneurysmal bone cyst. In the remaining cases, the differential diagnosis may include other primary spinal tumors, vertebral metastases and major nontumoral lesions simulating a vertebral tumor, Paget disease, spondylitis, echinococcal infection, and aseptic osteitis. In many cases, vertebral biopsy is warranted to guide treatment.

Grasping convergent evolution in syngnathids: a unique tale of tails.

PubMed

Neutens, C; Adriaens, D; Christiaens, J; De Kegel, B; Dierick, M; Boistel, R; Van Hoorebeke, L

2014-06-01

Seahorses and pipehorses both possess a prehensile tail, a unique characteristic among teleost fishes, allowing them to grasp and hold onto substrates such as sea grasses. Although studies have focused on tail grasping, the pattern of evolutionary transformations that made this possible is poorly understood. Recent phylogenetic studies show that the prehensile tail evolved independently in different syngnathid lineages, including seahorses, Haliichthys taeniophorus and several types of so-called pipehorses. This study explores the pattern that characterizes this convergent evolution towards a prehensile tail, by comparing the caudal musculoskeletal organization, as well as passive bending capacities in pipefish (representing the ancestral state), pipehorse, seahorse and H. taeniophorus. To study the complex musculoskeletal morphology, histological sectioning, μCT-scanning and phase contrast synchrotron scanning were combined with virtual 3D-reconstructions. Results suggest that the independent evolution towards tail grasping in syngnathids reflects at least two quite different strategies in which the ancestral condition of a heavy plated and rigid system became modified into a highly flexible one. Intermediate skeletal morphologies (between the ancestral condition and seahorses) could be found in the pygmy pipehorses and H. taeniophorus, which are phylogenetically closely affiliated with seahorses. This study suggests that the characteristic parallel myoseptal organization as already described in seahorse (compared with a conical organization in pipefish and pipehorse) may not be a necessity for grasping, but represents an apomorphy for seahorses, as this pattern is not found in other syngnathid species possessing a prehensile tail. One could suggest that the functionality of grasping evolved before the specialized, parallel myoseptal organization seen in seahorses. However, as the grasping system in pipehorses is a totally different one, this cannot be

Grasping convergent evolution in syngnathids: a unique tale of tails

PubMed Central

Neutens, C; Adriaens, D; Christiaens, J; De Kegel, B; Dierick, M; Boistel, R; Van Hoorebeke, L

2014-01-01

Seahorses and pipehorses both possess a prehensile tail, a unique characteristic among teleost fishes, allowing them to grasp and hold onto substrates such as sea grasses. Although studies have focused on tail grasping, the pattern of evolutionary transformations that made this possible is poorly understood. Recent phylogenetic studies show that the prehensile tail evolved independently in different syngnathid lineages, including seahorses, Haliichthys taeniophorus and several types of so-called pipehorses. This study explores the pattern that characterizes this convergent evolution towards a prehensile tail, by comparing the caudal musculoskeletal organization, as well as passive bending capacities in pipefish (representing the ancestral state), pipehorse, seahorse and H. taeniophorus. To study the complex musculoskeletal morphology, histological sectioning, μCT-scanning and phase contrast synchrotron scanning were combined with virtual 3D-reconstructions. Results suggest that the independent evolution towards tail grasping in syngnathids reflects at least two quite different strategies in which the ancestral condition of a heavy plated and rigid system became modified into a highly flexible one. Intermediate skeletal morphologies (between the ancestral condition and seahorses) could be found in the pygmy pipehorses and H. taeniophorus, which are phylogenetically closely affiliated with seahorses. This study suggests that the characteristic parallel myoseptal organization as already described in seahorse (compared with a conical organization in pipefish and pipehorse) may not be a necessity for grasping, but represents an apomorphy for seahorses, as this pattern is not found in other syngnathid species possessing a prehensile tail. One could suggest that the functionality of grasping evolved before the specialized, parallel myoseptal organization seen in seahorses. However, as the grasping system in pipehorses is a totally different one, this cannot be

Dendritic spine dynamics in synaptogenesis after repeated LTP inductions: Dependence on pre-existing spine density

PubMed Central

Oe, Yuki; Tominaga-Yoshino, Keiko; Hasegawa, Sho; Ogura, Akihiko

2013-01-01

Not only from our daily experience but from learning experiments in animals, we know that the establishment of long-lasting memory requires repeated practice. However, cellular backgrounds underlying this repetition-dependent consolidation of memory remain largely unclear. We reported previously using organotypic slice cultures of rodent hippocampus that the repeated inductions of LTP (long-term potentiation) lead to a slowly developing long-lasting synaptic enhancement accompanied by synaptogenesis distinct from LTP itself, and proposed this phenomenon as a model system suitable for the analysis of the repetition-dependent consolidation of memory. Here we examined the dynamics of individual dendritic spines after repeated LTP-inductions and found the existence of two phases in the spines' stochastic behavior that eventually lead to the increase in spine density. This spine dynamics occurred preferentially in the dendritic segments having low pre-existing spine density. Our results may provide clues for understanding the cellular bases underlying the repetition-dependent consolidation of memory. PMID:23739837

A visco-hyperelastic constitutive model for human spine ligaments.

PubMed

Jiang, Yugang; Wang, Yu; Peng, Xiongqi

2015-03-01

Human spine ligaments show a highly non-linear, strain rate dependent biomechanical behavior under tensile tests. A visco-hyperelastic fiber-reinforced constitutive model was accordingly developed for human ligaments, in which the energy density function is decomposed into two parts. The first part represents the elastic strain energy stored in the soft tissue, and the second part denotes the energy dissipated due to its inherent viscous characteristics. The model is applied to various human spinal ligaments including the anterior and posterior longitudinal ligaments, ligamentum flavum, capsular ligament, and interspinous ligament. Material parameters for each type of ligament were obtained by curve-fitting with corresponding experimental data available in the literature. The results indicate that the model presented here can properly characterize the visco-hyperelastic biomechanical behavior of human spine ligaments.

49 CFR 572.85 - Lumbar spine flexure.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) of this section, the lumbar spine assembly shall flex by an amount that permits the thoracic spine to... to the thoracic spine box. Apply the force at any torso deflection rate between 0.5 and 1.5 degrees... 49 Transportation 7 2011-10-01 2011-10-01 false Lumbar spine flexure. 572.85 Section 572.85...

MESSENGER Observations of Extreme Loading and Unloading of Mercury's Magnetic Tail

NASA Technical Reports Server (NTRS)

Slavin, James A.; Anderson, Brian J.; Baker, Daniel N.; Benna, Mehdi; Boardsen, Scott A.; Gloeckler, George; Gold, Robert E.; Ho, George C.; Korth, Haje; Krimigis, Stamatios M.;

Neural space and biomechanical integrity of the developing cervical spine in compression.

PubMed

Nuckley, David J; Van Nausdle, Joseph A; Eck, Michael P; Ching, Randal P

2007-03-15

A factorial study design was used to examine the biomechanical and neuroprotective integrity of the cervical spine throughout maturation using a postmortem baboon model. To investigate changes with spinal development that affect the neuroprotective ability of the cervical spine in compressive loading. Child spinal cord injuries claim and debilitate thousands of children in the United States each year. Many of these injuries are diagnostically and mechanistically difficult to classify, treat, and prevent. Biomechanical studies on maturing spinal tissues have identified decreased stiffness and tolerance characteristics for children compared with adults. Unfortunately, while neurologic deficit typically dictates functional outcome, no previous studies have examined the neuroprotective role of the pediatric cervical spine. Twenty-two postmortem baboon cervical spines across the developmental age spectrum were tested. Two functional spinal unit segments (Oc-C2, C3-C5, and C6-T1) were instrumented with transducers to measure dynamic changes in the spinal canal. These tissues were compressed to 70% strain dynamically, and the resultant mechanics and spinal canal occlusions were recorded. Classic injury patterns were observed in all of the specimens tested. The compressive mechanics exhibited a significant age relationship (P < 0.0001). Furthermore, while the peak-percent spinal canal occlusion was not age dependent, the percent occlusion just before failure did demonstrate a significant decrease with advancing age (P = 0.0001). The neuroprotective ability of the cervical spine preceding failure appears to be age dependent, where the young spine can produce greater spinal canal occlusions without failure than its adult counterpart. The overall percent of the spinal canal occluded during a compression injury was not age dependent; however, these data reveal the neuroprotective ability of the child spine to be more sensitive as an injury predictor than the biomechanical

Palmitoylation-dependent CDKL5-PSD-95 interaction regulates synaptic targeting of CDKL5 and dendritic spine development.

PubMed

Zhu, Yong-Chuan; Li, Dan; Wang, Lu; Lu, Bin; Zheng, Jing; Zhao, Shi-Lin; Zeng, Rong; Xiong, Zhi-Qi

2013-05-28

The X-linked gene cyclin-dependent kinase-like 5 (CDKL5) is mutated in severe neurodevelopmental disorders, including some forms of atypical Rett syndrome, but the function and regulation of CDKL5 protein in neurons remain to be elucidated. Here, we show that CDKL5 binds to the scaffolding protein postsynaptic density (PSD)-95, and that this binding promotes the targeting of CDKL5 to excitatory synapses. Interestingly, this binding is not constitutive, but governed by palmitate cycling on PSD-95. Furthermore, pathogenic mutations that truncate the C-terminal tail of CDKL5 diminish its binding to PSD-95 and synaptic accumulation. Importantly, down-regulation of CDKL5 by RNA interference (RNAi) or interference with the CDKL5-PSD-95 interaction inhibits dendritic spine formation and growth. These results demonstrate a critical role of the palmitoylation-dependent CDKL5-PSD-95 interaction in localizing CDKL5 to synapses for normal spine development and suggest that disruption of this interaction by pathogenic mutations may be implicated in the pathogenesis of CDKL5-related disorders.

Robotic systems in spine surgery.

PubMed

Onen, Mehmet Resid; Naderi, Sait

2014-01-01

Surgical robotic systems have been available for almost twenty years. The first surgical robotic systems were designed as supportive systems for laparoscopic approaches in general surgery (the first procedure was a cholecystectomy in 1987). The da Vinci Robotic System is the most common system used for robotic surgery today. This system is widely used in urology, gynecology and other surgical disciplines, and recently there have been initial reports of its use in spine surgery, for transoral access and anterior approaches for lumbar inter-body fusion interventions. SpineAssist, which is widely used in spine surgery, and Renaissance Robotic Systems, which are considered the next generation of robotic systems, are now FDA approved. These robotic systems are designed for use as guidance systems in spine instrumentation, cement augmentations and biopsies. The aim is to increase surgical accuracy while reducing the intra-operative exposure to harmful radiation to the patient and operating team personnel during the intervention. We offer a review of the published literature related to the use of robotic systems in spine surgery and provide information on using robotic systems.

Stability and control characteristics of an airplane model having a 45.1 degree swept-back wing with aspect ratio 2.50 and taper ratio 0.42 and a 42.8 degree swept-back horizontal tail with aspect ratio 3.87 and taper ratio 0.49

NASA Technical Reports Server (NTRS)

Schuldenfrei, Marvin; Comisarow, Paul; Goodson, Kenneth W

1947-01-01

Tests were made of an airplane model having a 45.1 degree swept-back wing with aspect ratio 2.50 and taper ratio 0.42 and a 42.8 degree swept-back horizontal tail with aspect ratio 3.87 and taper ratio 0.49 to determine its low-speed stability and control characteristics. The test Reynolds number was 2.87 x 10(6) based on a mean aerodynamic chord of 2.47 feet except for some of the aileron tests which were made at a Reynolds number of 2.05 x 10(6). With the horizontal tail located near the fuselage juncture on the vertical tail, model results indicated static longitudinal instability above a lift coefficient that was 0.15 below the lift coefficient at which stall occurred. Static longitudinal stability, however, was manifested throughout the life range with the horizontal tail located near the top of the vertical tail. The use of 10 degrees negative dihedral on the wing had little effect on the static longitudinal stability characteristics. Preliminary tests of the complete model revealed an undesirable flat spot in the yawing-moment curves at low angles of attack, the directional stability being neutral for yaw angles of plus-or-minus 2 degrees. This undesirable characteristic was improved by replacing the thick original vertical tail with a thin vertical tail and by flattening the top of the dorsal fairing.

Does applying the Canadian Cervical Spine rule reduce cervical spine radiography rates in alert patients with blunt trauma to the neck? A retrospective analysis.

PubMed

Rethnam, Ulfin; Yesupalan, Rajam; Gandham, Giri

2008-06-16

A cautious outlook towards neck injuries has been the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs for suspected neck injuries were included in the study. Data on patient demographics, high risk & low risk factors as per the Canadian Cervical Spine rule and cervical spine radiography results were collected and analysed. 28 patients were included in the high risk category according to the Canadian Cervical Spine rule. 86 patients fell into the low risk category. If the Canadian Cervical Spine rule was applied, there would have been a significant reduction in cervical spine radiographs as 86/114 patients (75.4%) would not have needed cervical spine radiograph. 2/114 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients would have reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and health care costs.

Flight dynamics of a pterosaur-inspired aircraft utilizing a variable-placement vertical tail.

PubMed

Roberts, Brian; Lind, Rick; Chatterjee, Sankar

2011-06-01

Mission performance for small aircraft is often dependent on the turn radius. Various biologically inspired concepts have demonstrated that performance can be improved by morphing the wings in a manner similar to birds and bats; however, the morphing of the vertical tail has received less attention since neither birds nor bats have an appreciable vertical tail. This paper investigates a design that incorporates the morphing of the vertical tail based on the cranial crest of a pterosaur. The aerodynamics demonstrate a reduction in the turn radius of 14% when placing the tail over the nose in comparison to a traditional aft-placed vertical tail. The flight dynamics associated with this configuration has unique characteristics such as a Dutch-roll mode with excessive roll motion and a skid divergence that replaces the roll convergence.

Three Dimensional Explicit Model for Cometary Tail Ions Interactions with Solar Wind

NASA Astrophysics Data System (ADS)

Al Bermani, M. J. F.; Alhamed, S. A.; Khalaf, S. Z.; Ali, H. Sh.; Selman, A. A.

2009-06-01

The different interactions between cometary tail and solar wind ions are studied in the present paper based on three-dimensional Lax explicit method. The model used in this research is based on the continuity equations describing the cometary tail-solar wind interactions. Three dimensional system was considered in this paper. Simulation of the physical system was achieved using computer code written using Matlab 7.0. The parameters studied here assumed Halley comet type and include the particle density rho, the particles velocity v, the magnetic field strength B, dynamic pressure p and internal energy E. The results of the present research showed that the interaction near the cometary nucleus is mainly affected by the new ions added to the plasma of the solar wind, which increases the average molecular weight and result in many unique characteristics of the cometary tail. These characteristics were explained in the presence of the IMF.

Does applying the Canadian Cervical Spine rule reduce cervical spine radiography rates in alert patients with blunt trauma to the neck? A retrospective analysis

PubMed Central

Rethnam, Ulfin; Yesupalan, Rajam; Gandham, Giri

2008-01-01

Background A cautious outlook towards neck injuries has been the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs for suspected neck injuries were included in the study. Data on patient demographics, high risk & low risk factors as per the Canadian Cervical Spine rule and cervical spine radiography results were collected and analysed. Results 28 patients were included in the high risk category according to the Canadian Cervical Spine rule. 86 patients fell into the low risk category. If the Canadian Cervical Spine rule was applied, there would have been a significant reduction in cervical spine radiographs as 86/114 patients (75.4%) would not have needed cervical spine radiograph. 2/114 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients would have reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and health care costs. PMID:18557998

[Abnormal growth of spine in patients with adolescent idiopathic thoracic scoliosis].

PubMed

Bao, Hongda; Liu, Zhen; Qiu, Yong; Zhu, Feng; Zhu, Zezhang; Zhang, Wen

2014-05-01

To investigate if the growth patterns of the spine and pelvis are consistent in adolescent idiopathic scoliosis (AIS) patients with single thoracic curves. Forty-eight thoracic adolescent idiopathic scoliosis (T-AIS) female patients and 48 healthy age-matched adolescents were recruited consecutively between December 2011 and October 2012. Radiographic parameters including height of spine (HOS), length of spine (LOS), height of thoracic spine (HOT), length of thoracic spine (LOT), height of pelvis (HOP), width of pelvis (WOP) and width of thorax (WOT) were measured on the long-cassette posteroanterior standing radiographs. In addition, ratios including HOS/HOP, LOS/HOP, HOT/HOP, LOT/HOP, LOS/LOT, WOT/WOP were also calculated. Independent t-test was performed to compare the radiographic parameters and ratios between the two groups. Compared to the age-matched healthy adolescents, T-AIS patients had a significantly higher LOS and LOT (t = -2.364 and -1.495, P = 0.020 and 0.043) and smaller HOS and HOT (t = 2.060 and 3.359, P = 0.042 and 0.001). Yet, all of HOP, WOP and WOT showed no significant difference between T-AIS patients and healthy adolescents. Similarly, LOS/HOP and LOT/HOP were significantly higher in T-AIS patients as may be expected with an average LOS/HOP of 2.26 ± 0.14 in normal controls.In addition, LOS/LOT in normal controls had a trend of increase with age which was different from the stable LOS/LOT in T-AIS patients, indicating an increased growth of thoracic vertebra compared to lumbar vertebra. Compared to the age-matched healthy adolescents, T-AIS patients have an abnormal growth characteristics with longer spine. The growth of pelvis and thorax show no significant differences between T-AIS patients and healthy adolescents.

Anatomy of large animal spines and its comparison to the human spine: a systematic review.

PubMed

Sheng, Sun-Ren; Wang, Xiang-Yang; Xu, Hua-Zi; Zhu, Guo-Qing; Zhou, Yi-Fei

2010-01-01

Animal models have been commonly used for in vivo and in vitro spinal research. However, the extent to which animal models resemble the human spine has not been well known. We conducted a systematic review to compare the morphometric features of vertebrae between human and animal species, so as to give some suggestions on how to choose an appropriate animal model in spine research. A literature search of all English language peer-reviewed publications was conducted using PubMed, OVID, Springer and Elsevier (Science Direct) for the years 1980-2008. Two reviewers extracted data on the anatomy of large animal spines from the identified articles. Each anatomical study of animals had to include at least three vertebral levels. The anatomical data from all animal studies were compared with the existing data of the human spine in the literature. Of the papers retrieved, seven were included in the review. The animals in the studies involved baboon, sheep, porcine, calf and deer. Distinct anatomical differences of vertebrae were found between the human and each large animal spine. In cervical region, spines of the baboon and human are more similar as compared to other animals. In thoracic and lumbar regions, the mean pedicle height of all animals was greater than the human pedicles. There was similar mean pedicle width between animal and the human specimens, except in thoracic segments of sheep. The human spinal canal was wider and deeper in the anteroposterior plane than any of the animals. The mean human vertebral body width and depth were greater than that of the animals except in upper thoracic segments of the deer. However, the mean vertebral body height was lower than that of all animals. This paper provides a comprehensive review to compare vertebrae geometries of experimental animal models to the human vertebrae, and will help for choosing animal model in vivo and in vitro spine research. When the animal selected for spine research, the structural similarities and

Collar spine models in the genus Echinostoma (Trematoda: Echinostomatidae).

PubMed

Kanev, Ivan; Fried, Bernard; Radev, Valentin

2009-10-01

This paper discusses collar spine arrangements in the genus Echinostoma. All arrangements are of uneven numbers of collar spines on the oral collar. The total number of collar spines in these arrangements ranges from a low 31 to a high 51. There are 11 models of collar spine arrangements in the Echinostoma consisting of spine numbers 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, and 51. Representative species with these collar spine arrangements are given in the article. The number of collar spines in a species is identical in both the larval and adult forms. Reports of even numbered spine counts in the genus Echinostoma are erroneous and probably reflect counts on worms with lost, retracted, or supernumerary spines.

The profit motive and spine surgery.

PubMed

Weiner, Bradley K; Levi, Benjamin H

2004-11-15

The profit motive and market medicine have had a significant impact on clinical practice and research in the field of spine surgery. An overview of current concerns is presented. The objective of this study was to provide those involved in the study and treatment of spinal disorders with a critical overview of the effects of the profit motive on our practices. Historically, the profit motive has been viewed as eroding the standards of spine surgery, encouraging surgeons to operate aggressively and researchers to bias their results. Although there are legitimate concerns regarding the role played by such market forces, the profit motive exerts several quite positive effects on spine surgery as well. Negative and positive aspects of the profit motive in spine surgery are explored along with alternative approaches. The profit motive in spine surgery can result in unnecessary surgery, as well as the push to market of unproven technologies. Yet, without a robust profit motive, it is unclear where sufficient funding could be found to support research and education, and to underwrite the advancement of new technologies. The profit motive significantly influences the way we practice and conduct research in spine surgery. To minimize the negative aspects of the profit motive, spine surgeons and researchers must refrain from being used by companies to rush products to market and/or compromising patient care out of self-interest.

Multidrug-resistant tuberculosis of the spine--is it the beginning of the end? A study of twenty-five culture proven multidrug-resistant tuberculosis spine patients.

PubMed

Pawar, Uday M; Kundnani, Vishal; Agashe, Vikas; Nene, Amita; Nene, Abhay

2009-10-15

Prospective cohort study. We report the first study of multidrug-resistant tuberculosis (MDR-TB) in the spine. The aim was to determine the clinical, radiologic, and drug resistance profile as well as the factors associated with treatment outcome of MDR-TB in the spine. Tuberculosis of the spine is the most common extrapulmonary form of tuberculosis in the Asian subcontinent. The disease in few cases is resistant to the primary anti-Koch's medications and the number of cases detected is on the rise. Multidrug resistant form of tuberculosis of the spine is ill reported in the literature. The diagnosis, management thus remains a challenge to the treating surgeon. This study tries to assess these critical issues of this "new" disease. Described here are the clinical characteristics of 25 MDR-TB spine patients identified in the study and their drug susceptibility patterns. They were followed up clinically, radiologically after a biopsy, culture, and Drug Susceptibility Testing. According to their Drug Susceptibility Testing pattern and previous history of Anti-Tubercular Treatment (ATT), individualized treatment regimens were tailored for each patient by an expert physician. Majority of the patients seen in the present study were in the productive years of their life. (Males (9) mean age: 38.5 years and females (16) mean age: 34.3 years. Four patients were defaulters of the ATT. The average number of drugs used was 6, including 4 second line drugs. Average treatment duration was 24 months. Almost 50% of the patients had adverse drug effects. Of the 25 patients, 19 achieved healed status and 6 are still on treatment. Four patients required surgery for mechanical instability of the spine. Radiologic improvement was observed in all the cases after a mean treatment of 6 months. Five predictors were identified for successful outcome of MDR-TB. They include progressive clinical improvement at 6 months, radiologic improvement during treatment and disease with Mycobacterium

Case reviews of infections of the spine in patients with a history of solid organ transplantation.

PubMed

Falakassa, Jonathan; Hirsch, Brandon P; Norton, Robert P; Mendez-Zfass, Matthew; Eismont, Frank J

2014-09-01

Retrospective clinical case series. To report on the epidemiological, microbiological, and clinical characteristics of spinal infections in patients who have undergone solid organ transplantation. Spine infections remain a therapeutic challenge, particularly in patients who are immunocompromised. Solid organ transplant patients represent a growing population of immunocompromised hosts. To our knowledge, no previous reports have examined the clinical characteristics spinal infections in this at-risk population in a systematic fashion. The records of patients with a history of solid organ transplantation from January 2007 through December 2012 were identified using Current Procedural Terminology procedure codes. Patients with spine infections who have received transplants were then identified using International Classification of Diseases, Ninth Revision codes for spine infection. In addition to demographic data, we recorded medical comorbidities, immunosuppressant medications, laboratory results, culture data, treatment received, and short-term results. During this 6-year period, 2764 solid organ transplants were performed at our institution. Of this cohort, 6 patients (0.22%) were treated for a spinal infection. Patient's age ranged from 51 to 80 years (mean, 63 yr). All spine infections occurred within 1 year after organ transplantation. All patients had an elevated erythrocyte sedimentation rate. Only 1 patient had an elevated white blood cell count. The most common organisms were Escherichia coli and Staphylococcus. Four patients required surgical treatment. All patients had complete resolution of symptoms. Our data suggest that patients with a history of solid organ transplantation may be more susceptible to developing spine infections than the general population. The most common organisms in our cohort were E. coli and Staphylococcus. Spine infections caused by atypical organisms do also occur in the organ transplant population, as is the case in other

Automated 4D analysis of dendritic spine morphology: applications to stimulus-induced spine remodeling and pharmacological rescue in a disease model

PubMed Central

2011-01-01

Uncovering the mechanisms that regulate dendritic spine morphology has been limited, in part, by the lack of efficient and unbiased methods for analyzing spines. Here, we describe an automated 3D spine morphometry method and its application to spine remodeling in live neurons and spine abnormalities in a disease model. We anticipate that this approach will advance studies of synapse structure and function in brain development, plasticity, and disease. PMID:21982080

[Iliac spine fractures in children].

PubMed

Sułko, Jerzy; Olipra, Wojciech

2010-01-01

Iliac spine fractures in children are a form of avulsion fractures at mechanically weak spot caused by the presence of the growth plate. Presentation of observations concerning treatment and results of iliac spine fractures in children. 49 children (1 girl and 48 boys). Age, at the time of injury, average 15.1 years (10.6-18 years). We analyzed medical and radiological documentation of patients. 17 patients sustained anterior superior iliac spine fractures (ASIS), 32 fracture of the inferior iliac spine (AIIS). Most of injuries happened during sport activities--27 patients suffered fracture while playing football. 37 patients asked for medical advice immediately after the injury. Rest of patients, who came late--sustained AIIS fracture. We hospitalized 26 patients (53%), all of them suffered significant pain. The average length of stay in hospital was 8 days. All patients were treated conservatively. All of the fractures healed without complications. Larger study than ours group, concerning 84 patients with iliac spine fractures, was presented only by Italian authors who analyzed injures of professional athletes. In literature reviewed conservative treatment strongly predominates. Only a small group of patients were treated surgically (including athletes treated by Croatian surgeons). The treatment of iliac spines in children should be conservative, consisting of a couple days of bed rest and then for 2-3 weeks walking on crutches with only toe touching until the pain resolves. We recommend return to full activities after 2 months.

Survival rates, mortality causes, and habitats of Pennsylvania white-tailed deer fawns

USGS Publications Warehouse

Vreeland, J.K.; Diefenbach, D.R.; Wallingford, B.D.

2004-01-01

Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocollared neonatal (0.05). Predation accounted for 46.2% (95% Cl = 37.6-56.7%) of 106 mortalities through 34 weeks. We attributed 32.7% (95% Cl = 21.9-48.6%) and 36.7% (95% Cl = 25.5-52.9%) of 49 predation events to black bears (Ursus americanus) and coyotes (Canis latrans], respectively. Natural causes, excluding predation, accounted for 27.4% (95% Cl = 20.1-37.3) of mortalities. Fawn survival in Pennsylvania was comparable to reported survival in forested and agricultural regions in northern portions of the white-tailed deer range. We have no evidence to suggest that the fawn survival rates we observed were preventing population growth. Because white-tailed deer are habitat generalists, home-range-scale habitat characteristics may be unrelated to fawn survival; therefore, future studies should consider landscape-related characteristics on fawn survival.

Diagnostic Approach to Pediatric Spine Disorders.

PubMed

Rossi, Andrea; Martinetti, Carola; Morana, Giovanni; Severino, Mariasavina; Tortora, Domenico

2016-08-01

Understanding the developmental features of the pediatric spine and spinal cord, including embryologic steps and subsequent growth of the osteocartilaginous spine and contents is necessary for interpretation of the pathologic events that may affect the pediatric spine. MR imaging plays a crucial role in the diagnostic evaluation of patients suspected of harboring spinal abnormalities, whereas computed tomography and ultrasonography play a more limited, complementary role. This article discusses the embryologic and developmental anatomy features of the spine and spinal cord, together with some technical points and pitfalls, and the most common indications for pediatric spinal MR imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Palmitoylation-dependent CDKL5–PSD-95 interaction regulates synaptic targeting of CDKL5 and dendritic spine development

PubMed Central

Zhu, Yong-Chuan; Li, Dan; Wang, Lu; Lu, Bin; Zheng, Jing; Zhao, Shi-Lin; Zeng, Rong; Xiong, Zhi-Qi

2013-01-01

The X-linked gene cyclin-dependent kinase-like 5 (CDKL5) is mutated in severe neurodevelopmental disorders, including some forms of atypical Rett syndrome, but the function and regulation of CDKL5 protein in neurons remain to be elucidated. Here, we show that CDKL5 binds to the scaffolding protein postsynaptic density (PSD)-95, and that this binding promotes the targeting of CDKL5 to excitatory synapses. Interestingly, this binding is not constitutive, but governed by palmitate cycling on PSD-95. Furthermore, pathogenic mutations that truncate the C-terminal tail of CDKL5 diminish its binding to PSD-95 and synaptic accumulation. Importantly, down-regulation of CDKL5 by RNA interference (RNAi) or interference with the CDKL5–PSD-95 interaction inhibits dendritic spine formation and growth. These results demonstrate a critical role of the palmitoylation-dependent CDKL5–PSD-95 interaction in localizing CDKL5 to synapses for normal spine development and suggest that disruption of this interaction by pathogenic mutations may be implicated in the pathogenesis of CDKL5-related disorders. PMID:23671101

Pathological characteristics of spine metastases treated with high-dose single-fraction stereotactic radiosurgery.

PubMed

Katsoulakis, Evangelia; Laufer, Ilya; Bilsky, Mark; Agaram, Narasimhan P; Lovelock, Michael; Yamada, Yoshiya

2017-01-01

OBJECTIVE Spine radiosurgery is increasingly being used to treat spinal metastases. As patients are living longer because of the increasing efficacy of systemic agents, appropriate follow-up and posttreatment management for these patients is critical. Tumor progression after spine radiosurgery is rare; however, vertebral compression fractures are recognized as a more common posttreatment effect. The use of radiographic imaging alone posttreatment may makeit difficult to distinguish tumor progression from postradiation changes such as fibrosis. This is the largest series from a prospective database in which the authors examine histopathology of samples obtained from patients who underwent surgical intervention for presumed tumor progression or mechanical pain secondary to compression fracture. The majority of patients had tumor ablation and resulting fibrosis rather than tumor progression. The aim of this study was to evaluate tumor histopathology and characteristics of patients who underwent pathological sampling because of radiographic tumor progression, fibrosis, or collapsed vertebrae after receiving high-dose single-fraction stereotactic radiosurgery. METHODS Between January 2005 and January 2014, a total of 582 patients were treated with linear accelerator-based single-fraction (18-24 Gy) stereotactic radiosurgery. The authors retrospectively identified 30 patients (5.1%) who underwent surgical intervention for 32 lesions with vertebral cement augmentation for either mechanical pain or instability secondary to vertebral compression fracture (n = 17) or instrumentation (n = 15) for radiographic tumor progression. Radiation and surgical treatment, histopathology, and long-term outcomes were reviewed. Survival and time to recurrence were calculated using the Kaplan-Meier method. RESULTS The mean age at the time of radiosurgery was 59 years (range 36-80 years). The initial pathological diagnoses were obtained for all patients and primarily included radioresistant

Pathological characteristics of spine metastases treated with high-dose single-fraction stereotactic radiosurgery

PubMed Central

Katsoulakis, Evangelia; Laufer, Ilya; Bilsky, Mark; Agaram, Narasimhan P.; Lovelock, Michael; Yamada, Yoshiya

2017-01-01

OBJECTIVE Spine radiosurgery is increasingly being used to treat spinal metastases. As patients are living longer because of the increasing efficacy of systemic agents, appropriate follow-up and posttreatment management for these patients is critical. Tumor progression after spine radiosurgery is rare; however, vertebral compression fractures are recognized as a more common posttreatment effect. The use of radiographic imaging alone posttreatment may make it difficult to distinguish tumor progression from postradiation changes such as fibrosis. This is the largest series from a prospective database in which the authors examine histopathology of samples obtained from patients who underwent surgical intervention for presumed tumor progression or mechanical pain secondary to compression fracture. The majority of patients had tumor ablation and resulting fibrosis rather than tumor progression. The aim of this study was to evaluate tumor histopathology and characteristics of patients who underwent pathological sampling because of radiographic tumor progression, fibrosis, or collapsed vertebrae after receiving high-dose single-fraction stereotactic radiosurgery. METHODS Between January 2005 and January 2014, a total of 582 patients were treated with linear accelerator–based single-fraction (18–24 Gy) stereotactic radiosurgery. The authors retrospectively identified 30 patients (5.1%) who underwent surgical intervention for 32 lesions with vertebral cement augmentation for either mechanical pain or instability secondary to vertebral compression fracture (n = 17) or instrumentation (n = 15) for radiographic tumor progression. Radiation and surgical treatment, histopathology, and long-term outcomes were reviewed. Survival and time to recurrence were calculated using the Kaplan-Meier method. RESULTS The mean age at the time of radiosurgery was 59 years (range 36–80 years). The initial pathological diagnoses were obtained for all patients and primarily included

Clostridium difficile colitis in patients undergoing lumbar spine surgery.

PubMed

Skovrlj, Branko; Guzman, Javier Z; Silvestre, Jason; Al Maaieh, Motasem; Qureshi, Sheeraz A

2014-09-01

Retrospective database analysis. To investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after lumbar spine surgery. C. difficile colitis is reportedly increasing in hospitalized patients and can have a negative impact on patient outcomes. No data exist on estimates of C. difficile infection rates and its consequences on patient outcomes and health care resources among patients undergoing lumbar spine surgery. The Nationwide Inpatient Sample was examined from 2002 to 2011. Patients were included for study based on International Classification of Diseases, Ninth Revision, Clinical Modification, procedural codes for lumbar spine surgery for degenerative diagnoses. Baseline patient characteristics were determined and multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. The incidence of C. difficile infection in patients undergoing lumbar spine surgery is 0.11%. At baseline, patients infected with C. difficile were significantly older (65.4 yr vs. 58.9 yr, P<0.0001) and more likely to have diabetes with chronic complications, neurological complications, congestive heart failure, pulmonary disorders, coagulopathy, and renal failure. Lumbar fusion (P=0.0001) and lumbar fusion revision (P=0.0003) were associated with increased odds of postoperative infection. Small hospital size was associated with decreased odds (odds ratio [OR], 0.5; P<0.001), whereas urban hospitals were associated with increased odds (OR, 2.14; P<0.14) of acquiring infection. Uninsured (OR, 1.62; P<0.0001) and patients with Medicaid (OR, 1.33; P<0.0001) were associated with higher odds of acquiring postoperative infection. C. difficile increased hospital length of stay by 8 days (P<0.0001), hospital charges by 2-fold (P<0.0001), and inpatient mortality to 4% from 0.11% (P<0.0001). C. difficile infection after lumbar spine surgery carries a 36.4-fold increase in mortality and costs

Wind-tunnel investigation at supersonic speeds of a remote-controlled canard missile with a free-rolling-tail brake torque system

NASA Technical Reports Server (NTRS)

Blair, A. B., Jr.

1985-01-01

Wind tunnel tests were conducted at Mach numbers 1.70, 2.16, and 2.86 to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed or free rolling tailfin afterbodies. Mechanical coupling effects of the free-rolling-tail afterbody were investigated by using an electronic electromagnetic brake system providing arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail roll rate. Remote-controlled canards were deflected to provide pitch, yaw, and roll control. Results indicate that the induced rolling moment coefficients due to canard yaw control are reduced and linearized for the free-rolling-tail (free-tail) configuration. The canards of the latter provide conventional roll control for the entire angle-of-attack test range. For the free-tail configuration, the induced rolling moment coefficient due to canard yaw control increased and the canard roll control decreased with increases in brake torque, which simulated bearing friction torque. It appears that a compromise in regard to bearing friction, for example, low-cost bearings with some friction, may allow satisfactory free-tail aerodynamic characteristics that include reductions in adverse rolling-moment coefficients and lower tail roll rates.

Failure Analysis on Tail Rotor Teeter Pivot Bolt on a Helicopter

NASA Astrophysics Data System (ADS)

Qiang, WANG; Zi-long, DONG

2018-03-01

Tail rotor teeter pivot bolt of a helicopter fractured when in one flight. Failure analysis on the bolt was finished in laboratory. Macroscopic observation of the tailor rotor teeter pivot bolt, macro and microscopic inspection on the fracture surface of the bolt was carried out. Chemical components and metallurgical structure was also carried out. Experiment results showed that fracture mode of the tail rotor teeter pivot bolt is fatigue fracture. Fatigue area is over 80% of the total fracture surface, obvious fatigue band characteristics can be found at the fracture face. According to the results were analyzed from the macroscopic and microcosmic aspects, fracture reasons of the tail rotor teeter pivot bolt were analyzed in detail

A Tale of Two Tails: Exploring Stellar Populations in the Tidal Tails of NGC 3256

NASA Astrophysics Data System (ADS)

Rodruck, Michael; Charlton, Jane C.; Konstantopoulos, Iraklis

2016-01-01

Galaxy interactions can inject material into the intergalactic medium via violent gravitational dynamics, often visualized in tidal tails. The composition of these tails has remained a mystery, as previous studies have focused on detecting tidal features, rather than the composite material itself. We have developed an observing program using deep, multiband imaging to probe the chaotic regions of tidal tails in search for an underlying stellar population. NGC 3256's twin tidal tails serve as a case study for this new technique. Our results show color values of u - g = 1.15 and r - i = 0.08 for the Western tail, and u - g = 1.33 and r - i = 0.22 for the Eastern tail, corresponding to discrepant ages between the tails of approximately 320 Myr and 785 Myr, respectively. With the interaction age of the system measured at 400 Myr, we find the stellar light in Western tail to be dominated by disrupted star clusters formed during and after the interaction, whereas the light from the Eastern tail is dominated by a 10 Gyr population originating from the host galaxies. We fit the Eastern tail color to a Mixed Stellar Population (MSP) model comprised 94% by mass of a 10 Gyr stellar population, and 6% of a 309 Myr population. We find 52% of the bolometric flux originating from this 10 Gyr population. We also detect a blue to red color gradient in each tail, running from galactic center to tail tip. In addition to tidal tail light, we detect 29 star cluster candidates (SCCs) in the Western tail and 19 in the Eastern, with mean ages of 282 Myr and 98 Myr respectively. Interestingly, we find an excess of very blue SCCs in the Eastern tail as compared to the Western tail, marking a recent, small episode of star formation.

Occurrence of Greater Sage-Grouse X Sharp-tailed Grouse hybrids in Alberta

USGS Publications Warehouse

Aldridge, Cameron L.; Oyler-McCance, S.J.; Brigham, R.M.

2001-01-01

Two distinct grouse were regularly observed at two Greater Sage-Grouse (Centrocercus urophasianus) leks in both 1999 and 2000 in southeastern Alberta. Physically and behaviorally, the birds exhibited characteristics of both Greater Sage-Grouse and Sharp-tailed Grouse (Tympanuchus phasianellus), suggesting they were hybrids. DNA analyses of blood and feather samples indicated that both birds were males with Greater Sage-Grouse mothers and thus, fathers that were likely Sharp-tailed Grouse.

Conspicuous and aposematic spines in the animal kingdom

NASA Astrophysics Data System (ADS)

Inbar, Moshe; Lev-Yadun, Simcha

2005-04-01

Spines serve as a common physical defence mechanism in both the plant and animal kingdoms. Here we argue that as in plants, defensive animal spines are often conspicuous (shape and colour) and should be considered aposematic. Conspicuous spines may evolve as signals or serve as a cue for potential predators. Spine conspicuousness in animals has evolved independently across and within phyla occupying aquatic and terrestrial ecosystems, indicating that this convergent phenomenon is highly adaptive. Still, many spines are cryptic, suggesting that conspicuity is not simply constrained by developmental factors such as differences in the chemical composition of the integument. Aposematism does not preclude the signalling role of conspicuous spines in the sexual arena.

The Study of Cobb Angular Velocity in Cervical Spine during Dynamic Extension-Flexion.

PubMed

Ren, Dong; Hu, Zhihao; Yuan, Wen

2016-04-01

A kinematic study of cervical spine. The aim of the study was to confirm the interesting manifestation observed in the dynamic images of the cervical spine movement from full-extension to full-flexion. To further explore the fine motion of total process of cervical spine movement with the new concept of Cobb angular velocity (CAV). Traditionally range of motion (ROM) is used to describe the cervical spine movement from extension to flexion. It is performed with only end position radiographs. However, these radiographs fail to explain how the elaborate movement happens. The dynamic images of the cervical spine movement from full-extension to full-flexion of 12 asymptomatic subjects were collected. After transforming these dynamic images to static lateral radiographs, we overlapped C7 cervical vertebrae of each subject and divided the total process of cervical spine movement into five equal partitions. Finally, CAV values from C2/3 to C6/7 were measured and analyzed. A broken line graph was created based on the data of CAV values. A simple motion process was observed in C2/3 and C3/4 segments. The motion processes of C4/5 and C5/6 segments exhibited a more complex track of "N" and "W" than the other segments. The peak CAV values of C4/5 and C5/6 were significantly greater than the other segments. From C2/3 to C6/7, the peak CAV value appeared in sequence. The intervertebral movements of cervical spine did not take a uniform motion form when the cervical spine moved from full-extension to full-flexion. From C2/3 to C6/7, the peak CAV value appeared in order. The C4/5 and C5/6 segments exhibited more complex kinematic characteristics in sagittal movement. This leads to C4/5 and C5/6 more vulnerable to injury and degeneration. We had a hypothesis that there was a positive correlation between injury/degeneration and complexity of intervertebral movement in the view of CAV. N/A.

The Degenerative Spine.

PubMed

Clarençon, Frédéric; Law-Ye, Bruno; Bienvenot, Peggy; Cormier, Évelyne; Chiras, Jacques

2016-08-01

Degenerative disease of the spine is a leading cause of back pain and radiculopathy, and is a frequent indication for spine MR imaging. Disc degeneration, disc protrusion/herniation, discarhtrosis, spinal canal stenosis, and facet joint arthrosis, as well as interspinous processes arthrosis, may require an MR imaging workup. This review presents the MR imaging patterns of these diseases and describes the benefit of the MR imaging in these indications compared with the other imaging modalities like plain radiographs or computed tomography scan. Copyright © 2016 Elsevier Inc. All rights reserved.

Unusual development of light-reflecting pigment cells in intact and regenerating tail in the periodic albino mutant of Xenopus laevis.

PubMed

Fukuzawa, Toshihiko

2010-10-01

Unusual light-reflecting pigment cells, "white pigment cells", specifically appear in the periodic albino mutant (a(p) /a(p)) of Xenopus laevis and localize in the same place where melanophores normally differentiate in the wild-type. The mechanism responsible for the development of unusual pigment cells is unclear. In this study, white pigment cells in the periodic albino were compared with melanophores in the wild-type, using a cell culture system and a tail-regenerating system. Observations of both intact and cultured cells demonstrate that white pigment cells are unique in (1) showing characteristics of melanophore precursors at various stages of development, (2) accumulating reflecting platelets characteristic of iridophores, and (3) exhibiting pigment dispersion in response to α-melanocyte stimulating hormone (α-MSH) in the same way that melanophores do. When a tadpole tail is amputated, a functionally competent new tail is regenerated. White pigment cells appear in the mutant regenerating tail, whereas melanophores differentiate in the wild-type regenerating tail. White pigment cells in the mutant regenerating tail are essentially similar to melanophores in the wild-type regenerating tail with respect to their localization, number, and response to α-MSH. In addition to white pigment cells, iridophores which are never present in the intact tadpole tail appear specifically in the somites near the amputation level in the mutant regenerating tail. Iridophores are distinct from white pigment cells in size, shape, blue light-induced fluorescence, and response to α-MSH. These findings strongly suggest that white pigment cells in the mutant arise from melanophore precursors and accumulate reflecting platelets characteristic of iridophores.

Unusual development of light-reflecting pigment cells in intact and regenerating tail in the periodic albino mutant of Xenopus laevis

PubMed Central

2010-01-01

Unusual light-reflecting pigment cells, “white pigment cells”, specifically appear in the periodic albino mutant (ap/ap) of Xenopus laevis and localize in the same place where melanophores normally differentiate in the wild-type. The mechanism responsible for the development of unusual pigment cells is unclear. In this study, white pigment cells in the periodic albino were compared with melanophores in the wild-type, using a cell culture system and a tail-regenerating system. Observations of both intact and cultured cells demonstrate that white pigment cells are unique in (1) showing characteristics of melanophore precursors at various stages of development, (2) accumulating reflecting platelets characteristic of iridophores, and (3) exhibiting pigment dispersion in response to α-melanocyte stimulating hormone (α-MSH) in the same way that melanophores do. When a tadpole tail is amputated, a functionally competent new tail is regenerated. White pigment cells appear in the mutant regenerating tail, whereas melanophores differentiate in the wild-type regenerating tail. White pigment cells in the mutant regenerating tail are essentially similar to melanophores in the wild-type regenerating tail with respect to their localization, number, and response to α-MSH. In addition to white pigment cells, iridophores which are never present in the intact tadpole tail appear specifically in the somites near the amputation level in the mutant regenerating tail. Iridophores are distinct from white pigment cells in size, shape, blue light-induced fluorescence, and response to α-MSH. These findings strongly suggest that white pigment cells in the mutant arise from melanophore precursors and accumulate reflecting platelets characteristic of iridophores. PMID:20859642

Cost Analysis of Spinal Versus General Anesthesia for Lumbar Diskectomy and Laminectomy Spine Surgery.

PubMed

Agarwal, Prateek; Pierce, John; Welch, William C

2016-05-01

Lumbar spine surgery can be performed using various anesthetic modalities, most notably general or spinal anesthesia. Because data comparing the cost of these anesthetic modalities in spine surgery are scarce, this study asks whether spinal anesthesia is less costly than general anesthesia. A total of 542 patients who underwent elective lumbar diskectomy or laminectomy spine surgery between 2007 and 2011 were retrospectively identified, with 364 having received spinal anesthesia and 178 having received general anesthesia. Mean direct operating cost, indirect cost (general support staff, insurance, taxes, floor space, facility, and administrative costs), and total cost were compared among patients who received general and spinal anesthesia. Linear multiple regression analysis was used to identify the effect of anesthesia type on cost and determine the factors underlying this effect, while controlling for patient and procedure characteristics. When controlling for patient and procedure characteristics, use of spinal anesthesia was associated with a 41.1% lower direct operating cost (-$3629 ± $343, P < 0.001), 36.6% lower indirect cost (-$1603 ± $168, P < 0.001), and 39.6% lower total cost (-$5232 ± $482, P < 0.001) compared with general anesthesia. Shorter hospital stay, shorter duration of anesthesia, shorter duration of operation, and lower estimated blood loss contributed to lower costs for spinal anesthesia, but other factors beyond these were also responsible for lower direct operating and total costs. When comparing the benefits of spinal and general anesthesia, spinal anesthesia is less costly when used in patients undergoing lumbar diskectomy and laminectomy spine surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Lumbar Spine Injury/Pathology as a Predictor of Outcomes in National Football League Athletes

PubMed Central

Lynch, Thomas Sean; Schroeder, Greg; Gibbs, Daniel; Chow, Ian; LaBelle, Mark; Savage, Jason W.; Patel, Alpesh; Hsu, Wellington; Nuber, Gordon W.

2014-01-01

Objectives: The purpose of this study is to determine if a pre-existing lumbar diagnosis such as spondylosis, a herniated lumbar disc, or spondylolysis affects a football player’s draft status or his performance and longevity in the NFL. Methods: The written medical evaluations and imaging reports of prospective professional American football athletes from 2003-2011 from one NFL franchise during the NFL combine (annual college football player evaluation prior to the NFL draft) were compiled and evaluated. All players were evaluated for a pre-existing lumbar diagnosis which were compiled from previous injury/medical records including radiographic imaging reports. Those players with a lumbar spine diagnosis and with appropriate radiograph, MRI and CT imaging were included in this study. These athletes were then matched by age, position, year, and round drafted to control draftees without a lumbar spine diagnosis. Career statistics were compiled including length of play and number of games started. Additionally, a previously established “Performance Score” was calculated for all players excluding offensive linemen. The continuous variables of each cohort were compared using a two-sided (tailed) Student’s t-test for normally distributed data. A chi-squared analysis was performed to analyze the categorical data. Statistical significance was accepted with a p < 0.05. Results: Out of a total of 2,965 athletes evaluated from the NFL combine, 414 players were identified with a pre-existing lumbar spine diagnosis. Athletes who attended the NFL combine without a lumbar spine diagnosis were significantly more likely to be drafted than those with one (74% vs. 61% respectively, p < 0.01). There was no difference between the investigational and control group with regard to round drafted, age, year drafted, or position. Overall, athletes with a lumbar spine injury compared to the control group had no difference in the number of years played (4.0 vs. 4.3 years, respectively

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses.

PubMed

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-09-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.

Vertebral artery injury associated with blunt cervical spine trauma: a multivariate regression analysis.

PubMed

Lebl, Darren R; Bono, Christopher M; Velmahos, George; Metkar, Umesh; Nguyen, Joseph; Harris, Mitchel B

2013-07-15

Retrospective analysis of prospective registry data. To determine the patient characteristics, risk factors, and fracture patterns associated with vertebral artery injury (VAI) in patients with blunt cervical spine injury. VAI associated with cervical spine trauma has the potential for catastrophical clinical sequelae. The patterns of cervical spine injury and patient characteristics associated with VAI remain to be determined. A retrospective review of prospectively collected data from the American College of Surgeons trauma registries at 3 level-1 trauma centers identified all patients with a cervical spine injury on multidetector computed tomographic scan during a 3-year period (January 1, 2007, to January 1, 2010). Fracture pattern and patient characteristics were recorded. Logistic multivariate regression analysis of independent predictors for VAI and subgroup analysis of neurological events related to VAI was performed. Twenty-one percent of 1204 patients with cervical injuries (n = 253) underwent screening for VAI by multidetector computed tomography angiogram. VAI was diagnosed in 17% (42 of 253), unilateral in 15% (38 of 253), and bilateral in 1.6% (4 of 253) and was associated with a lower Glasgow coma scale (P < 0.001), a higher injury severity score (P < 0.01), and a higher mortality (P < 0.001). VAI was associated with ankylosing spondylitis/diffuse idiopathic skeletal hyperosteosis (crude odds ratio [OR] = 8.04; 95% confidence interval [CI], 1.30-49.68; P = 0.034), and occipitocervical dissociation (P < 0.001) by univariate analysis and fracture displacement into the transverse foramen 1 mm or more (adjusted OR = 3.29; 95% CI, 1.15-9.41; P = 0.026), and basilar skull fracture (adjusted OR = 4.25; 95% CI, 1.25-14.47; P= 0.021), by multivariate regression model. Subgroup analyses of neurological events secondary to VAI occurred in 14% (6 of 42) and the stroke-related mortality rate was 4.8% (2 of 42). Neurological events were associated with male sex (P

Dendritic spine dysgenesis in Autism Related Disorders

PubMed Central

Phillips, Mary; Pozzo-Miller, Lucas

2015-01-01

The activity-dependent structural and functional plasticity of dendritic spines has led to the long-standing belief that these neuronal compartments are the subcellular sites of learning and memory. Of relevance to human health, central neurons in several neuropsychiatric illnesses, including autism related disorders, have atypical numbers and morphologies of dendritic spines. These so-called dendritic spine dysgeneses found in individuals with autism related disorders are consistently replicated in experimental mouse models. Dendritic spine dysgenesis reflects the underlying synaptopathology that drives clinically relevant behavioral deficits in experimental mouse models, providing a platform for testing new therapeutic approaches. By examining molecular signaling pathways, synaptic deficits, and spine dysgenesis in experimental mouse models of autism related disorders we find strong evidence for mTOR to be a critical point of convergence and promising therapeutic target. PMID:25578949

Absence of clinical findings reliably excludes unstable cervical spine injuries in children 5 years or younger.

PubMed

Hale, Diane F; Fitzpatrick, Colleen M; Doski, John J; Stewart, Ronald M; Mueller, Deborah L

2015-05-01

Increased accessibility and rapidity of computed tomography (CT) have led to increased use and radiation exposure to pediatric trauma patients. The thyroid is radiosensitive and therefore at risk for developing malignancy from radiation exposure during cervical spine CT. This analysis aimed to determine which preelementary trauma patients warrant cervical spine CT by defining incidence and clinical characteristics of preelementary cervical spine injury. This was a retrospective review of pre-elementary trauma patients from 1998 to 2010 with cervical spine injury admitted to a Level I trauma center. Patients were identified from the trauma registry using DRG International Classification of Diseases-9th Rev. codes and reviewed for demographics, mechanism of injury, clinical presentation, injury location, injury type, treatment, and outcome. A total of 2,972 preelementary trauma patients were identified. Twenty-two (0.74%) had confirmed cervical spine injuries. Eleven (50%) were boys, and the mean (SD) age was 3 (1.7) years. The most common mechanism of injury was motor vehicle collision (n = 16, 73%). The majority (59%) were in extremis, and 12 (55%) arrived intubated. The median Glasgow Coma Scale (GCS) score was 3 (interquartile range, 3-10); the median Injury Severity Score (ISS) was 33 (interquartile range, 17-56). Nineteen injuries (76%) were at the level of C4 level and higher. The mortality rate was 50%. All patients had clinical findings suggestive of or diagnostic for cervical spine injury; 18 (82%) had abnormal neurologic examination result, 2 (9%) had torticollis, and 2 (9%) had neck pain. The incidence of cervical spine injury in preelementary patients was consistent with previous reports. Missing a cervical spine injury in asymptomatic preelementary patients is extremely low. Reserving cervical spine CT to symptomatic preelementary patients would decrease unnecessary radiation exposure to the thyroid. Therapeutic study, level IV.

Static strain and vibration characteristics of a metal semimonocoque helicopter tail cone of moderate size

NASA Technical Reports Server (NTRS)

Bielawa, Richard L.; Hefner, Rachel E.; Castagna, Andre

1991-01-01

The results are presented of an analytic and experimental research program involving a Sikorsky S-55 helicopter tail cone directed ultimately to the improved structural analysis of airframe substructures typical of moderate sized helicopters of metal semimonocoque construction. Experimental static strain and dynamic shake-testing measurements are presented. Correlation studies of each of these tests with a PC-based finite element analysis (COSMOS/M) are described. The tests included static loadings at the end of the tail cone supported in the cantilever configuration as well as vibrational shake-testing in both the cantilever and free-free configurations.

Low-speed wind tunnel investigation of the static stability and control characteristics of an advanced turboprop configuration with the propellers placed over the tail. M.S. Thesis

NASA Technical Reports Server (NTRS)

Rhodes, Graham Scott

1990-01-01

An exploratory wind tunnel investigation was performed in the 30 x 60 foot wind tunnel to determine the low speed static stability and control characteristics into the deep stall regime of an advanced turboprop aircraft with the propellers located over the horizontal tail. By this arrangement, the horizontal tail could potentially provide acoustic shielding to reduce the high community noise caused by the propeller blades. The current configuration was a generic turboprop model equipped with 1 foot diameter single rotating eight bladed propellers that were designed for efficient cruise operation at a Mach number of 0.8. The data presented is static force data. The effects of power on the configuration characteristics were generally favorable. An arrangement with the propellers rotating with the outboard blades moving down was found to have significantly higher installed thrust than an arrangement with the propellers rotating with the inboard blades moving down. The primary unfavorable effect was a large pitch trim change which occurred with power, but the trim change could be minimized with a proper configuration design.

Surgical apgar score in patients undergoing lumbar fusion for degenerative spine diseases.

PubMed

Ou, Chien-Yu; Hsu, Shih-Yuan; Huang, Jian-Hao; Huang, Yu-Hua

2017-01-01

Lumbar fusion is a procedure broadly performed for degenerative diseases of spines, but it is not without significant morbidities. Surgical Apgar Score (SAS), based on intraoperative blood loss, blood pressure, and heart rate, was developed for prognostic prediction in general and vascular operations. We aimed to examine whether the application of SAS in patients undergoing fusion procedures for degeneration of lumbar spines predicts in-hospital major complications. One hundred and ninety-nine patients that underwent lumbar fusion operation for spine degeneration were enrolled in this retrospective study. Based on whether major complications were present (N=16) or not (N=183), the patients were subdivided. We identified the intergroup differences in SAS and clinical parameters. The incidence of in-hospital major complications was 8%. The duration of hospital stay for the morbid patents was significantly prolonged (p=0.04). In the analysis of multivariable logistic regression, SAS was an independent predicting factor of the complications after lumbar fusion for degenerative spine diseases [p=0.001; odds ratio (95% confidence interval)=0.35 (0.19-0.64)]. Lower scores were accompanied with higher rates of major complications, and the area was 0.872 under the receiver operating characteristic curve. SAS is an independent predicting factor of major complications in patients after fusion surgery for degenerative diseases of lumbar spines, and provides good risk discrimination. Since the scoring system is relatively simple, objective, and practical, we suggest that SAS be included as an indicator in the guidance for level of care after lumbar fusion surgery. Copyright © 2016 Elsevier B.V. All rights reserved.

Dielectric relaxation in undiluted poly (4-chlorostyrene). II. Characteristics of the high frequency tail

NASA Astrophysics Data System (ADS)

Yoshihara, M.; Work, R. N.

1981-05-01

The shape of the principal dielectric relaxation process that occurs just above the glass transition temperature Tg in well annealed, atactic, undiluted poly (4-chlorostyrene) exhibits a small tail at the high frequency end of the spectrum of relaxation times. This high frequency tail (HFT) has been characterized at temperatures varying from 351 to 413 K by using the Havriliak-Negami equation. The glass transition temperature Tg of P4CS is about 400 K. It is suggested that the HFT is distinct from the β relaxation process which occurs in polystyrene at temperatures just below Tg; and that the HFT is experimental evidence of the existence of localized, fast conformational changes. This fast process is presumed to be slowed and broadened by interactions with the surroundings.

Establishment of Hox vertebral identities in the embryonic spine precursors

PubMed Central

Iimura, Tadahiro; Denans, Nicolas; Pourquié, Olivier

2012-01-01

Summary The vertebrate spine exhibits two striking characteristics. The first one is the periodic arrangement of its elements – the vertebrae – along the antero-posterior axis. This segmented organization is the result of somitogenesis, which takes place during organogenesis. The segmentation machinery involves a molecular oscillator – the segmentation clock – which delivers a periodic signal controlling somite production. During embryonic axis elongation, this signal is displaced posteriorly by a system of traveling signaling gradients – the wavefront – which depends on the Wnt, FGF and retinoic acid pathways. The other characteristic feature of the spine is the subdivision of groups of vertebrae into anatomical domains, such as the cervical, thoracic, lumbar, sacral and caudal regions. This axial regionalization is controlled by a set of transcription factors called Hox genes. Hox genes exhibit nested expression domains in the somites which reflect their linear arrangement along the chromosomes– a property termed colinearity. The colinear disposition of Hox genes expression domains provides a blueprint for the regionalization of the future vertebral territories of the spine. In amniotes, Hox genes are activated in the somite precursors of the epiblast in a temporal colinear sequence and they were proposed to control their progressive ingression into the nascent paraxial mesoderm. Consequently, the positioning of the expression domains of Hox genes along the antero-posterior axis is largely controlled by the timing of Hox activation during gastrulation. Positioning of the somitic Hox domains is subsequently refined through a cross talk with the segmentation machinery in the presomitic mesoderm. In this review, we focus on our current understanding of the embryonic mechanisms that establish vertebral identities during vertebrate development. PMID:19651306

Vertebral hemangiomas: their demographical characteristics, location along the spine and position within the vertebral body.

PubMed

Slon, Viviane; Stein, Dan; Cohen, Haim; Sella-Tunis, Tatiana; May, Hila; Hershkovitz, Israel

2015-10-01

Vertebral hemangiomas (VHs) are the most common form of benign tumors in the spine. The aim of this research was to study the prevalence of VHs in the human population, their distribution along the spine and their location in the vertebral body. The presence of VHs was assessed in full spine CT scans of 196 adults. Demographic data were gathered from medical records. VHs were present in 26.0% of the individuals studied, a rate significantly higher (χ2=43.338, p<0.001) than the prevalence reported in the literature (10.7%). Multiple VHs (≥2) appeared in 7.2% of the population studied. VHs prevalence is sex-independent, appearing in 28.6% of females and 23.5% of males (χ2=0.663, p=0.416); and age-dependent: the mean age of affected individuals (65.8 years) was significantly higher (p<0.001) than unaffected individuals (56.2 years). VH size was also age-dependent (p=0.023). No vertebra was significantly more prone to be affected by a hemangioma. T11 and T12 show the highest prevalence of VHs (3.57% of vertebrae affected). VHs were found in similar percentages in the anterior and posterior parts of the vertebral body (52.8 vs. 47.2%, respectively); and at its center and periphery (50.1 and 49.9%, respectively). VHs usually appeared at mid-height of the vertebral body or slightly higher. The reported prevalence of VHs is dependent on the demographic structure of the population studied, the size of the VHs and the method used to identify them. Overall, the phenomenon is more frequent than usually reported. VHs may appear at all vertebral levels and in all areas of the vertebral body.

Evidence and practice in spine registries

PubMed Central

van Hooff, Miranda L; Jacobs, Wilco C H; Willems, Paul C; Wouters, Michel W J M; de Kleuver, Marinus; Peul, Wilco C; Ostelo, Raymond W J G; Fritzell, Peter

2015-01-01

Background and purpose We performed a systematic review and a survey in order to (1) evaluate the evidence for the impact of spine registries on the quality of spine care, and with that, on patient-related outcomes, and (2) evaluate the methodology used to organize, analyze, and report the “quality of spine care” from spine registries. Methods To study the impact, the literature on all spinal disorders was searched. To study methodology, the search was restricted to degenerative spinal disorders. The risk of bias in the studies included was assessed with the Newcastle-Ottawa scale. Additionally, a survey among registry representatives was performed to acquire information about the methodology and practice of existing registries. Results 4,273 unique references up to May 2014 were identified, and 1,210 were eligible for screening and assessment. No studies on impact were identified, but 34 studies were identified to study the methodology. Half of these studies (17 of the 34) were judged to have a high risk of bias. The survey identified 25 spine registries, representing 14 countries. The organization of these registries, methods used, analytical approaches, and dissemination of results are presented. Interpretation We found a lack of evidence that registries have had an impact on the quality of spine care, regardless of whether intervention was non-surgical and/or surgical. To improve the quality of evidence published with registry data, we present several recommendations. Application of these recommendations could lead to registries showing trends, monitoring the quality of spine care given, and ultimately improving the value of the care given to patients with degenerative spinal disorders. PMID:25909475

Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

PubMed

Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

2016-07-15

The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dendritic spine dysgenesis in autism related disorders.

PubMed

Phillips, Mary; Pozzo-Miller, Lucas

2015-08-05

The activity-dependent structural and functional plasticity of dendritic spines has led to the long-standing belief that these neuronal compartments are the subcellular sites of learning and memory. Of relevance to human health, central neurons in several neuropsychiatric illnesses, including autism related disorders, have atypical numbers and morphologies of dendritic spines. These so-called dendritic spine dysgeneses found in individuals with autism related disorders are consistently replicated in experimental mouse models. Dendritic spine dysgenesis reflects the underlying synaptopathology that drives clinically relevant behavioral deficits in experimental mouse models, providing a platform for testing new therapeutic approaches. By examining molecular signaling pathways, synaptic deficits, and spine dysgenesis in experimental mouse models of autism related disorders we find strong evidence for mTOR to be a critical point of convergence and promising therapeutic target. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Accountable disease management of spine pain.

PubMed

Smith, Matthew J

2011-09-01

The health care landscape has changed with new legislation addressing the unsustainable rise in costs in the US system. Low-value service lines caring for expensive chronic conditions have been targeted for reform; for better or worse, the treatment of spine pain has been recognized as a representative example. Examining the Patient Protection and Affordable Care Act and existing pilot studies can offer a preview of how chronic care of spine pain will be sustained. Accountable care in an organization capable of collecting, analyzing, and reporting clinical data and operational compliance is forthcoming. Interdisciplinary spine pain centers integrating surgical and medical management, behavioral medicine, physical reconditioning, and societal reintegration represent the model of high-value care for patients with chronic spine pain. Copyright © 2011 Elsevier Inc. All rights reserved.

Spine Injuries Sustained by U.S. Military Personnel in Combat are Different From Non-Combat Spine Injuries.

PubMed

Szuflita, Nicholas S; Neal, Chris J; Rosner, Michael K; Frankowski, Ralph F; Grossman, Robert G

2016-10-01

Spine injuries are more prevalent among Iraq and Afghanistan veterans than among veterans of previous conflicts. The purpose of this investigation was to characterize the context, mode, and clinical outcomes of spine injuries sustained by U.S. military personnel in theater. Injury and clinical data from patients who sustained a spine injury in Iraq or Afghanistan between 2003 and 2008 were extracted from the Joint Theater Trauma Registry. Fischer's exact test was used to compare demographic variables between battle and nonbattle spine injuries. Two-sided t tests and univariate analyses were performed to analyze the association between injury context, mechanism, and severity with clinical outcome. A total of 307 patients sustained spine injuries in theater during the study period, and 296 had adequate data for analysis. Most injuries occurred in battle (69.6%), and these injuries were more likely to have an Injury Severity Score considered severe (44.7% vs. 20.0%; p < 0.001) or critical (13.6% vs. 5.6%; p = 0.0458). Blast was the most common mechanism of injury (42.2%) and was more likely to be blunt (81.6%) than penetrating (18.4%; p < 0.0001). Battle-associated spine injuries were most commonly caused by blasts, were more severe, and more likely to involve multiple spinal levels. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Identification and mapping of ts (tender spines), a gene involved in soft spine development in Cucumis sativus.

PubMed

Guo, Chunli; Yang, Xuqin; Wang, Yunli; Nie, Jingtao; Yang, Yi; Sun, Jingxian; Du, Hui; Zhu, Wenying; Pan, Jian; Chen, Yue; Lv, Duo; He, Huanle; Lian, Hongli; Pan, Junsong; Cai, Run

2018-01-01

Using map-based cloning of ts gene, we identified a new sort of gene involved in the initiation of multicellular tender spine in cucumber. The cucumber (Cucumis sativus L.) fruit contains spines on the surface, which is an extremely valuable quality trait affecting the selection of customers. In this study, we elaborated cucumber line NC072 with wild type (WT) hard fruit spines and its spontaneous mutant NC073, possessing tender and soft spines on fruits. The mutant trait was named as tender spines (ts), which is controlled by a single recessive nuclear gene. We identified the gene ts by map-based cloning with an F 2 segregating population of 721 individuals generated from NC073 and WT line SA419-2. It was located between two markers Indel6239679 and Indel6349344, 109.7 kb physical distance on chromosome 1 containing fifteen putative genes. With sequencing and quantitative reverse transcription-polymerase chain reaction analysis, the Csa1G056960 gene was considered as the most possible candidate gene of ts. In the mutant, Csa1G056960 has a nucleotide change in the 5' splicing site of the second intron, which causes different splicing to delete the second exon, resulting in a N-terminal deletion in the predicted amino acid sequence. The gene encodes a C-type lectin receptor-like tyrosine-protein kinase which would play an important role in the formation of cucumber fruit. This is firstly reported of a receptor kinase gene regulating the development of multicellular spines/trichomes in plants. The ts allele could accelerate the molecular breeding of cucumber soft spines.

Psychological distress in the active duty military spine patient.

PubMed

Brooks, D Ethan; Agochukwu, Uzondu F; Arrington, Edward D; Mok, James M

2013-10-01

Disorders of the spine are a substantial burden to the military health care system that degrades readiness in the overall force. Because treatment outcomes are affected by psychosocial factors, assessment of psychological distress is important for patients with spine complaints. The incidence of psychological distress in the unique military population is not well described. The purpose of this retrospective case-control study was to determine the rate of psychological distress and identify associated patient characteristics among many variables collected in the military health system. A consecutive cohort of active duty service members presenting to a spine specialty clinic was assessed as Normal, At Risk, or Distressed using the Distress and Risk Assessment Method. Of 74 active duty patients (63 male, 11 female), 43 (58%) had some level of psychological distress: 29 (39%) At Risk, 12 (16%) Distressed-Depressive, and 2 (3%) Distressed-Somatic. Multivariate regression analysis identified female gender (odds ratio [OR] 7.90), higher disability as measured by Oswestry Disability Index/Neck Disability Index (OR 8.0 per 13.8 point increase), and assignment to a Warrior Transition Unit or Medical Evaluation Board (OR 7.35) as statistically significant variables. The results indicate that active duty patients are subject to similarly high levels of psychological distress as their civilian counterparts. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

History of spine biomechanics: part I--the pre-Greco-Roman, Greco-Roman, and medieval roots of spine biomechanics.

PubMed

Naderi, Sait; Andalkar, Niteen; Benzel, Edward C

2007-02-01

The roots of spine biomechanics reside in the Antiquity and the Medieval and Renaissance periods. A review of historical treatises reveals detailed information regarding this often historically neglected discipline. Ancient medical, philosophical, and physical documents were reviewed, as they pertained to the historical foundation of spine biomechanics. These included medical case reports and observations of nature and motion by ancient philosophers and scientists. These documents heavily influenced the portion of the scientific literature that we now regard as "spine biomechanics" up through the Renaissance. The focus of Part I of this two-part series is placed on the ancient and medieval biomechanics-related literature and on associated literature that influenced the development of the field of modern spine biomechanics.

Cervical Spine Instrumentation in Children.

PubMed

Hedequist, Daniel J; Emans, John B

2016-06-01

Instrumentation of the cervical spine enhances stability and improves arthrodesis rates in children undergoing surgery for deformity or instability. Various morphologic and clinical studies have been conducted in children, confirming the feasibility of anterior or posterior instrumentation of the cervical spine with modern implants. Knowledge of the relevant spine anatomy and preoperative imaging studies can aid the clinician in understanding the pitfalls of instrumentation for each patient. Preoperative planning, intraoperative positioning, and adherence to strict surgical techniques are required given the small size of children. Instrumentation options include anterior plating, occipital plating, and a variety of posterior screw techniques. Complications related to screw malposition include injury to the vertebral artery, neurologic injury, and instrumentation failure.

Dendritic spine geometry can localize GTPase signaling in neurons

PubMed Central

Ramirez, Samuel A.; Raghavachari, Sridhar; Lew, Daniel J.

2015-01-01

Dendritic spines are the postsynaptic terminals of most excitatory synapses in the mammalian brain. Learning and memory are associated with long-lasting structural remodeling of dendritic spines through an actin-mediated process regulated by the Rho-family GTPases RhoA, Rac, and Cdc42. These GTPases undergo sustained activation after synaptic stimulation, but whereas Rho activity can spread from the stimulated spine, Cdc42 activity remains localized to the stimulated spine. Because Cdc42 itself diffuses rapidly in and out of the spine, the basis for the retention of Cdc42 activity in the stimulated spine long after synaptic stimulation has ceased is unclear. Here we model the spread of Cdc42 activation at dendritic spines by means of reaction-diffusion equations solved on spine-like geometries. Excitable behavior arising from positive feedback in Cdc42 activation leads to spreading waves of Cdc42 activity. However, because of the very narrow neck of the dendritic spine, wave propagation is halted through a phenomenon we term geometrical wave-pinning. We show that this can account for the localization of Cdc42 activity in the stimulated spine, and, of interest, retention is enhanced by high diffusivity of Cdc42. Our findings are broadly applicable to other instances of signaling in extreme geometries, including filopodia and primary cilia. PMID:26337387

A Comparison of Cervical Spine Motion After Immobilization With a Traditional Spine Board and Full-Body Vacuum-Mattress Splint.

PubMed

Etier, Brian E; Norte, Grant E; Gleason, Megan M; Richter, Dustin L; Pugh, Kelli F; Thomson, Keith B; Slater, Lindsay V; Hart, Joe M; Brockmeier, Stephen F; Diduch, David R

2017-12-01

The National Athletic Trainers' Association (NATA) advocates for cervical spine immobilization on a rigid board or vacuum splint and for removal of athletic equipment before transfer to an emergency medical facility. To (1) compare triplanar cervical spine motion using motion capture between a traditional rigid spine board and a full-body vacuum splint in equipped and unequipped athletes, (2) assess cervical spine motion during the removal of a football helmet and shoulder pads, and (3) evaluate the effect of body mass on cervical spine motion. Controlled laboratory study. Twenty healthy male participants volunteered for this study to examine the influence of immobilization type and presence of equipment on triplanar angular cervical spine motion. Three-dimensional cervical spine kinematics was measured using an electromagnetic motion analysis system. Independent variables included testing condition (static lift and hold, 30° tilt, transfer, equipment removal), immobilization type (rigid, vacuum-mattress), and equipment (on, off). Peak sagittal-, frontal-, and transverse-plane angular motions were the primary outcome measures of interest. Subjective ratings of comfort and security did not differ between immobilization types ( P > .05). Motion between the rigid board and vacuum splint did not differ by more than 2° under any testing condition, either with or without equipment. In removing equipment, the mean peak motion ranged from 12.5° to 14.0° for the rigid spine board and from 11.4° to 15.4° for the vacuum-mattress splint, and more transverse-plane motion occurred when using the vacuum-mattress splint compared with the rigid spine board (mean difference, 0.14 deg/s [95% CI, 0.05-0.23 deg/s]; P = .002). In patients weighing more than 250 lb, the rigid board provided less motion in the frontal plane ( P = .027) and sagittal plane ( P = .030) during the tilt condition and transfer condition, respectively. The current study confirms similar motion in the

Measuring spine fracture outcomes: common scales and checklists.

PubMed

Schoenfeld, Andrew J; Bono, Christopher M

2011-03-01

Although outcome instruments have been used extensively in spine surgical research, few studies at present specifically address their use in investigations regarding spine trauma. In this review we provide a summary of the outcome instruments used most frequently in spine trauma research, identify the unique challenges of studying outcomes of spine trauma patients, and propose an integrated approach that may be beneficial for future studies. We reviewed the use of outcome instruments applicable to spine trauma research, including generic health measures, inventories of back-specific function, pain scales, health related quality of life (HRQOL) instruments, and radiographic determinants of outcome. Several inventories have been utilised to measure clinical outcomes following spinal trauma. Excluding measures of neurological function (e.g. ASIA motor score), none have been specifically validated for use with spine fractures. The SF-36, RMDQ, and ODI are amongst the most commonly used instruments. Importantly, the use of validated functional outcome measures in spine trauma research is hampered by the fact that the pre-morbid state of patients who sustain spine trauma may not be accurately represented by normative values established for the general population. The VAS is used most frequently to assess degree of neck and back pain. Most studies have relied on non-validated measures to determine radiographic results of treatment, although more elegant radiographic metrics exist. Functional outcome measurement of traumatically injured spine patients is challenging because available generic and spine-specific instruments were not designed for or validated in this population. Furthermore, no single inventory is capable of capturing global data necessary to evaluate results following these injuries. Investigations seeking to quantify outcomes following spine trauma should consider the use of a combination of existing surveys in a complementary fashion that should include a

The Tail Suspension Test

PubMed Central

Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

2012-01-01

The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test. PMID:22315011

High Frequency Tail Characteristics in the Coastal Waters off Gopalpur, Northwest Bay of Bengal: A Nearshore Modelling Study

NASA Astrophysics Data System (ADS)

Umesh, P. A.; Bhaskaran, Prasad K.; Sandhya, K. G.; Nair, T. M. Balakrishnan

2017-12-01

Over the years, continued uncertainty amid - 4 and - 5 frequency exponent representation observed in the slope of the high-frequency tail of a wind-wave frequency spectrum is a major concern. To comprehend the nature of the high-frequency tail an effort has been made to assess the slope of the high-frequency tail with measured data recorded for 3 years off Gopalpur. The study demonstrates that the high-frequency slope of the spectra varied seasonally in the range of n = - 2.13 to - 3.48. The swell and wind sea parameters calculated by separation frequency method, shows that 64.6% of waves were dominant by swell and the rest 34.9% by sea annually. Single, double and multi-peaked spectra occur 12.23, 71.80 and 15.37% annually. To simulate wave spectra, the nested WAM-SWAN model is forced with ERA-Interim winds and 1D wave spectra comparisons, when performed, proved to be encouraging. From the comparisons of measured and theoretical spectra it is concluded that JONSWAP model could not describe the high-frequency tail of measured spectrum, as indicated by the very high Scatter Index ranging from 0.24 to 1.44. Whether there exists a correct slope for the high-frequency tail is still a question. Moreover, the philosophy of a unique slope at any coastal location remains uncertain for the wave modelling community.

Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes

NASA Technical Reports Server (NTRS)

Riebe, John M; Naeseth, Rodger L

1953-01-01

An investigation was made in the Langley 300 mph 7-by 10-foot tunnel to determine the aerodynamic characteristics of a refined deep-step planing-tail hull with various forebody and afterbody shapes. For comparison, tests were made on a streamline body simulating the fuselage of a modern transport airplane. The results of the tests, which include the interference effects of a 21-percent-thick support wing, indicated that for corresponding configurations the hull models incorporating a forebody with a length-beam ratio of 7 had lower minimum drag coefficients than the hull models incorporating a forebody with a length-beam ratio of 5. Longitudinal and lateral stability was generally about the same for all hull models tested and about the same as that of a conventional hull.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses

PubMed Central

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-01-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51–92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research. PMID:23635867

Diagnosis of unstable cervical spine injuries: laboratory support for the use of axial traction to diagnose cervical spine instability.

PubMed

Kalantar, Babak S; Hipp, John A; Reitman, Charles A; Dreiangel, Niv; Ben-Galim, Peleg

2010-10-01

The ability to detect damage to the intervertebral structures is critical in the management of patients after blunt trauma. A practical and inexpensive method to identify severe structural damage not clearly seen on computed tomography would be of benefit. The objective of this study was to assess whether ligamentous injury in the subaxial cervical spine can be reliably detected by analysis of lateral radiographs taken with and without axial traction. Twelve fresh, whole, postrigor-mortis cadavers were used for this study. Lateral cervical spine radiographs were obtained during the application of 0 N, 89 N, and 178 N of axial traction applied to the head. Progressive incremental sectioning of posterior structures was then performed at C4-C5 with traction imaging repeated after each intervention. Intervertebral distraction was analyzed using computer-assisted software. Almost imperceptible intervertebral separation was found when traction was applied to intact spines. In the subaxial cervical spine, the average posterior disc height consistently increased under traction in severely injured spines. The average disc height increase was 14% of the C4 upper endplate width, compared with an average of 2% in the noninjured spines. A change of more than 5% in posterior disc height under traction was above the 95% confidence interval for intact spines, with sensitivity of 83% and specificity of 80%. Applied force of 89 N (20 lb) was sufficient to demonstrate injury. The combination of assessing alignment and distraction under traction increased both the sensitivity and specificity to nearly 100%. This study supports further clinical investigations to determine whether low-level axial traction may be a useful adjunct for detecting unstable subaxial cervical spine injuries in an acute setting.

Breeding biology and nest-site selection of red-tailed hawks in an altered desert grassland

USGS Publications Warehouse

Hobbs, R.J.; DeStefano, S.; Halvorson, W.L.

2006-01-01

Red-tailed Hawks (Buteo jamaicensis) have expanded their range as trees have invaded formerly-open grasslands. Desert grasslands of southern Arizona have been invaded by mesquite trees (Prosopis velutina) since Anglo-American settlement and now support a large population of Red-tailed Hawks. We studied a population of Red-tailed Hawks in an altered desert grassland in southern Arizona. Our objectives were to determine what environmental characteristics influence Red-tailed Hawk habitat selection in mesquite-invaded desert grasslands and to evaluate the habitat quality of these grasslands for Red-tailed Hawks based on nesting density, nest success, and productivity. Red-tailed Hawks had 86% (95% C.I. = 73-99) nest success and 1.82 young per breeding pair (95% C.I. = 1.41-2.23). Nesting density was 0.15 (95% CI = 0.08-0.21) breeding pairs/km2 and the mean nearest-neighbor distance was 1.95 km (95% C.I. = 1.74-2.16). Red-tailed Hawks selected nest-sites with taller nest-trees and greater tree height and cover than were available at random. Mesquite trees in desert grasslands provide abundant potential nesting structures for Red-tailed Hawks. ?? 2006 The Raptor Research Foundation, Inc.

The relationship between PSD-95 clustering and spine stability in vivo.

PubMed

Cane, Michele; Maco, Bohumil; Knott, Graham; Holtmaat, Anthony

2014-02-05

The appearance and disappearance of dendritic spines, accompanied by synapse formation and elimination may underlie the experience-dependent reorganization of cortical circuits. The exact temporal relationship between spine and synapse formation in vivo remains unclear, as does the extent to which synapse formation enhances the stability of newly formed spines and whether transient spines produce synapses. We used in utero electroporation of DsRedExpress- and eGFP-tagged postsynaptic density protein 95 (PSD-95) to investigate the relationship between spine and PSD stability in mouse neocortical L2/3 pyramidal cells in vivo. Similar to previous studies, spines and synapses appeared and disappeared, even in naive animals. Cytosolic spine volumes and PSD-95-eGFP levels in spines covaried over time, suggesting that the strength of many individual synapses continuously changes in the adult neocortex. The minority of newly formed spines acquired PSD-95-eGFP puncta. Spines that failed to acquire a PSD rarely survived for more than a day. Although PSD-95-eGFP accumulation was associated with increased spine lifetimes, most new spines with a PSD did not convert into persistent spines. This indicates that transient spines may serve to produce short-lived synaptic contacts. Persistent spines that were destined to disappear showed, on average, reduced PSD-95-eGFP levels well before the actual pruning event. Altogether, our data indicate that the PSD size relates to spine stability in vivo.

Most Cited Publications in Cervical Spine Surgery

PubMed Central

Brooks, Francis; Sandler, Simon; Yau, Yun-Hom; Selby, Michael; Freeman, Brian

2017-01-01

Purpose The purpose of this study is to perform a citation analysis on the most frequently cited articles in the topic of cervical spine surgery and report on the top 100 most cited publication in this topic. Methods We used the Thomson Reuters Web of Science to search citations of all articles from 1945 to 2015 relevant to cervical spine surgery and ranked them according to the number of citations. The 100 most cited articles that matched the search criteria were further analyzed by number of citations, first author, journal, year of publication, country and institution of origin. Results The top 100 cited articles in the topic of cervical spine surgery were published from 1952-2011. The number of citations ranged from 106 times for the 100th paper to 1206 times for the top paper. The decade of 1990-1999 saw the most publications. The Journal of Spine published the most articles, followed by Journal of Bone and Joint Surgery America. Investigators from America authored the most papers and The University of California contributed the most publications. Cervical spine fusion was the most common topic published with 36 papers, followed by surgical technique and trauma. Conclusion This article identifies the 100 most cited articles in cervical spine surgery. It has provided insight to the history and development in cervical spine surgery and many of which have shaped the way we practice today. PMID:28765803

High resolution flow field prediction for tail rotor aeroacoustics

NASA Technical Reports Server (NTRS)

Quackenbush, Todd R.; Bliss, Donald B.

1989-01-01

The prediction of tail rotor noise due to the impingement of the main rotor wake poses a significant challenge to current analysis methods in rotorcraft aeroacoustics. This paper describes the development of a new treatment of the tail rotor aerodynamic environment that permits highly accurate resolution of the incident flow field with modest computational effort relative to alternative models. The new approach incorporates an advanced full-span free wake model of the main rotor in a scheme which reconstructs high-resolution flow solutions from preliminary, computationally inexpensive simulations with coarse resolution. The heart of the approach is a novel method for using local velocity correction terms to capture the steep velocity gradients characteristic of the vortex-dominated incident flow. Sample calculations have been undertaken to examine the principal types of interactions between the tail rotor and the main rotor wake and to examine the performance of the new method. The results of these sample problems confirm the success of this approach in capturing the high-resolution flows necessary for analysis of rotor-wake/rotor interactions with dramatically reduced computational cost. Computations of radiated sound are also carried out that explore the role of various portions of the main rotor wake in generating tail rotor noise.

Muscle activity and spine load during pulling exercises: influence of stable and labile contact surfaces and technique coaching.

PubMed

McGill, Stuart M; Cannon, Jordan; Andersen, Jordan T

2014-10-01

This study examined pulling exercises performed on stable surfaces and unstable suspension straps. Specific questions included: which exercises challenged particular muscles, what was the magnitude of resulting spine load, and did technique coaching influence results. Fourteen males performed pulling tasks while muscle activity, external force, and 3D body segment motion were recorded. These data were processed and input to a sophisticated and anatomically detailed 3D model that used muscle activity and body segment kinematics to estimate muscle force, in this way the model was sensitive to each individual's choice of motor control for each task. Muscle forces and linked segment joint loads were used to calculate spine loads. There were gradations of muscle activity and spine load characteristics to every task. It appears that suspension straps alter muscle activity less in pulling exercises, compared to studies reporting on pushing exercises. The chin-up and pull-up exercises created the highest spine load as they required the highest muscle activation, despite the body "hanging" under tractioning gravitational load. Coaching shoulder centration through retraction increased spine loading but undoubtedly adds proximal stiffness. An exercise atlas of spine compression was constructed to help with the decision making process of exercise choice for an individual. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kinematic relationship between rotation of lumbar spine and hip joints during golf swing in professional golfers.

PubMed

Mun, Frederick; Suh, Seung Woo; Park, Hyun-Joon; Choi, Ahnryul

2015-05-14

Understanding the kinematics of the lumbar spine and hip joints during a golf swing is a basic step for identifying swing-specific factors associated with low back pain. The objective of this study was to examine the kinematic relationship between rotational movement of the lumbar spine and hip joints during a golf swing. Fifteen professional golfers participated in this study with employment of six infrared cameras to record their golf swings. Anatomical reference system of the upper torso, pelvis and thigh segments, and the location of each hip and knee joint were defined by the protocols of the kinematic model of previous studies. Lumbar spine and hip joint rotational angle was calculated utilizing the Euler angle method. Cross-correlation and angle-angle plot was used to examine the degree of kinematic relationship between joints. A fairly strong coupling relationship was shown between the lumbar spine and hip rotational movements with an average correlation of 0.81. Leading hip contribution to overall rotation was markedly high in the early stage of the downswing, while the lumbar spine contributed greater towards the end of the downswing; however, the relative contributions of the trailing hip and lumbar spine were nearly equal during the entire downswing. Most of the professional golfers participated in this study used a similar coordination strategy when moving their hips and lumbar spine during golf swings. The rotation of hips was observed to be more efficient in producing the overall rotation during the downswing when compared to the backswing. These results provide quantitative information to better understand the lumbar spine and hip joint kinematic characteristics of professional golfers. This study will have great potential to be used as a normal control data for the comparison with kinematic information among golfers with low back pain and for further investigation of golf swing-specific factors associated with injury.

Mechanics of biomimetic systems propelled by actin comet tails

NASA Astrophysics Data System (ADS)

Kang, Hyeran; Tambe, Dhananjay; Shenoy, Vivek; Tang, Jay

2009-03-01

The motility of intracellular bacterial pathogens such as Listeria monocytogenes is driven by filamentous actin comet tails in a variety of trajectories. Here, we present the in vitro study on the actin-based movements using spherical beads of different sizes coated with VCA protein, a partial domain of N-Wasp, in platelet extracts. Long term two-dimensional trajectories of the spherical beads motility show characteristic difference than those observed for bacteria, which have both elongated shape and asymmetric expression of the polymerization inducing enzyme. The trajectories also vary sensitively with the bead size and shape. These results provide a useful test to our new analytical model including the rotation of the bead relative to the tail.

Equal contributions and credit: an emerging trend in the characterization of authorship in major spine journals during a 10-year period.

PubMed

Jia, Zhiwei; Wu, Yaohong; Tang, Yong; Ji, Wei; Li, Wei; Zhao, Xiyan; Li, Hao; He, Qing; Ruan, Dike

2016-03-01

The practice of giving certain authors equal credit in scientific publications has become increasingly common in some medical specialties. However, whether this trend also exists in major spine journals remains unclear. This study aimed to investigate the prevalence and characteristics of the practice of giving authors equal credit in major spine journals. Manual searches were performed to identify original research articles with equally credited authors (ECA) published between January 1, 2004 and December 31, 2013 in three major spine journals: Spine, European Spine Journal, and The Spine Journal. The number of authors with ECA and their positions in the byline, total number of authors, year of publication, and country of origin were analysed. The practice of ECA was found in all three journals. Articles with ECA comprised a greater proportion of the total number of publications in each journal in 2013 versus 2004 (Spine, 7.2 vs. 0.2%; European Spine Journal, 7.5 vs. 0.0%; and The Spine Journal, 6.2 vs. 0.0%). There was a statistically significant increasing trend in the annual proportion of papers with ECA for all three spine journals (p < 0.0001). The practice of ECA was applied in nearly every position in the byline, and the first two authors received equal credit in most cases. Articles with ECA were published by authors from various countries and regions around the world. However, none of the three spine journals provided specific guidance on this practice in their author instructions. The practice of ECA in original research articles is increasingly common in major spine journals. A guideline for authors regarding when and how to designate equal credit is warranted in the future.

Acute and repeated activation of male sexual behavior by tail pinch: opioid and dopaminergic mechanisms.

PubMed

Leyton, M; Stewart, J

1996-07-01

We studied the effect of tail pinch on male sexual behavior and its neurochemical basis. Male rats were gonadectomized and maintained on low doses of testosterone propionate (20.0 micrograms/day). Tail pinch significantly increased the percentage of males that mounted, intromitted, and ejaculated within a 30-min test, and these increases were attenuated by both pimozide (1.0 mg/kg, i.p.) and by naloxone (0.5, 1.0, and 2.0 mg/kg, s.c.). Moreover, tail pinch in the presence of an estrous female led to significantly increased female-directed behavior 48 h later during a test without tail pinch. Repeated tail pinch tests led to progressively more sexual activity, and the development of this behavioral sensitization was prevented by naloxone. These findings suggest that tail pinch increases the salience of the incentive characteristics of the female. Furthermore, during subsequent tests, with or without tail pinch, the increased salience of the female remains, as measured by the continued increases in sexual activity. These acute and sensitized behavioral increases might result from tail pinch-induced activation of the midbrain dopamine system via an opioid mechanism; either preventing tail pinch-induced dopamine activation (by an opioid antagonist) or blocking the effects of dopamine activation (by a dopamine antagonist) attenuated the long-term facilitation of sexual behavior seen after pairing the female with tail pinch.

Changes in spine loading patterns throughout the workday as a function of experience, lift frequency, and personality.

PubMed

Chany, Anne-Marie; Parakkat, Julia; Yang, Gang; Burr, Deborah L; Marras, William S

2006-01-01

Psychosocial stressors have been associated with low back pain reporting. However, response to psychosocial risk factors may be dependent on the individual's personality type that, in turn, can affect muscle recruitment and spine loading. This study explores how personality might be associated with spine loading during repetitive lifting performed throughout an entire work shift. Assess spine loading as a function of an individual's personality type during repetitive, long-term exposure to a materials handling tasks. Laboratory experiment where experienced and inexperienced participants performed repetitive, asymmetric lifts at various load and lift frequency levels throughout a series of 8-hour exposure periods. Spine loads were monitored throughout the work period. Twelve novice and 12 experienced materials handlers who were asymptomatic for back pain. Spine compression, anterior-posterior (A/P) shear, and lateral shear at the L5-S1 level. Participants were categorized into personality types based upon the Myers-Briggs personality type indicator. An electromyography-assisted biomechanical model was used to assess spine compression, A/P shear, and lateral shear throughout the exposure period. The results indicate that intuitors had higher shear spinal loading regardless of moment exposure, lift frequency, and time through the work period, compared with the sensor personality type. In addition, higher spine compressive and shear forces occurred in the perceiver personality compared with the judgers' personality trait, regardless of moment and, often, lift frequency. Novice lifters typically experienced greater spine loading. The results suggest that when there exists a personality-job environment mismatch, spinal loading increases via an increase in antagonistic co-contraction. The trends suggest that inherent personality characteristics may play a role in one's motor control strategies when performing a repetitive lifting task.

Pollution characteristics of surface runoff under different restoration types in manganese tailing wasteland.

PubMed

Wang, Jun; Cheng, Qingyu; Xue, Shengguo; Rajendran, Manikandan; Wu, Chuan; Liao, Jiaxin

2018-04-01

A great deal of manganese and associated heavy metals (such as Ni, Cu, Zn, Cd, Pb, etc.) was produced in manganese mining, smelting, and other processes and weathering and leaching of waste slag, which entered rainwater runoff by different means under the action of rainfall runoff. It caused heavy metal pollution in water environment to surrounding areas, and then environmental and human health risks were becoming increasingly serious. In the Xiangtan manganese mine, we studied the characteristics of nutritional pollutants and heavy metals by using the method of bounded runoff plots on the manganese tailing wasteland after carrying out some site treatments using three different approaches, such as (1) exposed tailings, the control treatment (ET), (2) external-soil amelioration and colonization of Cynodon dactylon (Linn.) Pers. turf (EC), and (3) external-soil amelioration and seedling seeding propagation of Cynodon dactylon (Linn.) Pers. (ES). The research showed that the maximum runoff occurred in 20,140,712 rainfall events, and the basic law of runoff was EC area > ET area > ES area in the same rainfall event. The concentration of total suspended solids (TSS) and chemical oxygen demand (COD) of three ecological restoration areas adopted the following rule: ET area > EC area > ES area. Nitrogen (N) existed mainly in the form of water soluble while phosphorus (P) was particulate. The highest concentrations of total nitrogen (TN) and total phosphorus (TP) were 11.57 ± 2.99 mg/L in the EC area and 1.42 ± 0.56 mg/L in the ET area, respectively. Cr, Ni, Pb, Zn, Mn, and Cu in surface runoff from three restoration types all exceeded the class V level of the environmental quality standard for surface water except Cu in EC and ES areas. Pollution levels of heavy metals in surface runoff from three restoration areas are shown as follows: ET area > EC area > ES area. There was a significant positive correlation between TSS and runoff, COD, and TP. And this

Morphometric analysis of the developing pediatric cervical spine.

PubMed

Johnson, Kyle T; Al-Holou, Wajd N; Anderson, Richard C E; Wilson, Thomas J; Karnati, Tejas; Ibrahim, Mohannad; Garton, Hugh J L; Maher, Cormac O

2016-09-01

OBJECTIVE Our understanding of pediatric cervical spine development remains incomplete. The purpose of this analysis was to quantitatively define cervical spine growth in a population of children with normal CT scans. METHODS A total of 1458 children older than 1 year and younger than 18 years of age who had undergone a cervical spine CT scan at the authors' institution were identified. Subjects were separated by sex and age (in years) into 34 groups. Following this assignment, subjects within each group were randomly selected for inclusion until a target of 15 subjects in each group had been measured. Linear measurements were performed on the midsagittal image of the cervical spine. Twenty-three unique measurements were obtained for each subject. RESULTS Data showed that normal vertical growth of the pediatric cervical spine continues up to 18 years of age in boys and 14 years of age in girls. Approximately 75% of the vertical growth occurs throughout the subaxial spine and 25% occurs across the craniovertebral region. The C-2 body is the largest single-segment contributor to vertical growth, but the subaxial vertebral bodies and disc spaces also contribute. Overall vertical growth of the cervical spine throughout childhood is dependent on individual vertebral body growth as well as vertical growth of the disc spaces. The majority of spinal canal diameter growth occurs by 4 years of age. CONCLUSIONS The authors' morphometric analyses establish parameters for normal pediatric cervical spine growth up to 18 years of age. These data should be considered when evaluating children for potential surgical intervention and provide a basis of comparison for studies investigating the effects of cervical spine instrumentation and fusion on subsequent growth.

The fish tail motion forms an attached leading edge vortex

PubMed Central

Borazjani, Iman; Daghooghi, Mohsen

2013-01-01

The tail (caudal fin) is one of the most prominent characteristics of fishes, and the analysis of the flow pattern it creates is fundamental to understanding how its motion generates locomotor forces. A mechanism that is known to greatly enhance locomotor forces in insect and bird flight is the leading edge vortex (LEV) reattachment, i.e. a vortex (separation bubble) that stays attached at the leading edge of a wing. However, this mechanism has not been reported in fish-like swimming probably owing to the overemphasis on the trailing wake, and the fact that the flow does not separate along the body of undulating swimmers. We provide, to our knowledge, the first evidence of the vortex reattachment at the leading edge of the fish tail using three-dimensional high-resolution numerical simulations of self-propelled virtual swimmers with different tail shapes. We show that at Strouhal numbers (a measure of lateral velocity to the axial velocity) at which most fish swim in nature (approx. 0.25) an attached LEV is formed, whereas at a higher Strouhal number of approximately 0.6 the LEV does not reattach. We show that the evolution of the LEV drastically alters the pressure distribution on the tail and the force it generates. We also show that the tail's delta shape is not necessary for the LEV reattachment and fish-like kinematics is capable of stabilising the LEV. Our results suggest the need for a paradigm shift in fish-like swimming research to turn the focus from the trailing edge to the leading edge of the tail. PMID:23407826

Hippocampal Dendritic Spines Are Segregated Depending on Their Actin Polymerization

PubMed Central

Domínguez-Iturza, Nuria; Calvo, María; Benoist, Marion; Esteban, José Antonio; Morales, Miguel

2016-01-01

Dendritic spines are mushroom-shaped protrusions of the postsynaptic membrane. Spines receive the majority of glutamatergic synaptic inputs. Their morphology, dynamics, and density have been related to synaptic plasticity and learning. The main determinant of spine shape is filamentous actin. Using FRAP, we have reexamined the actin dynamics of individual spines from pyramidal hippocampal neurons, both in cultures and in hippocampal organotypic slices. Our results indicate that, in cultures, the actin mobile fraction is independently regulated at the individual spine level, and mobile fraction values do not correlate with either age or distance from the soma. The most significant factor regulating actin mobile fraction was the presence of astrocytes in the culture substrate. Spines from neurons growing in the virtual absence of astrocytes have a more stable actin cytoskeleton, while spines from neurons growing in close contact with astrocytes show a more dynamic cytoskeleton. According to their recovery time, spines were distributed into two populations with slower and faster recovery times, while spines from slice cultures were grouped into one population. Finally, employing fast lineal acquisition protocols, we confirmed the existence of loci with high polymerization rates within the spine. PMID:26881098

Automatic lumbar spine measurement in CT images

NASA Astrophysics Data System (ADS)

Mao, Yunxiang; Zheng, Dong; Liao, Shu; Peng, Zhigang; Yan, Ruyi; Liu, Junhua; Dong, Zhongxing; Gong, Liyan; Zhou, Xiang Sean; Zhan, Yiqiang; Fei, Jun

2017-03-01

Accurate lumbar spine measurement in CT images provides an essential way for quantitative spinal diseases analysis such as spondylolisthesis and scoliosis. In today's clinical workflow, the measurements are manually performed by radiologists and surgeons, which is time consuming and irreproducible. Therefore, automatic and accurate lumbar spine measurement algorithm becomes highly desirable. In this study, we propose a method to automatically calculate five different lumbar spine measurements in CT images. There are three main stages of the proposed method: First, a learning based spine labeling method, which integrates both the image appearance and spine geometry information, is used to detect lumbar and sacrum vertebrae in CT images. Then, a multiatlases based image segmentation method is used to segment each lumbar vertebra and the sacrum based on the detection result. Finally, measurements are derived from the segmentation result of each vertebra. Our method has been evaluated on 138 spinal CT scans to automatically calculate five widely used clinical spine measurements. Experimental results show that our method can achieve more than 90% success rates across all the measurements. Our method also significantly improves the measurement efficiency compared to manual measurements. Besides benefiting the routine clinical diagnosis of spinal diseases, our method also enables the large scale data analytics for scientific and clinical researches.

Random Positions of Dendritic Spines in Human Cerebral Cortex

PubMed Central

Morales, Juan; Benavides-Piccione, Ruth; Dar, Mor; Fernaud, Isabel; Rodríguez, Angel; Anton-Sanchez, Laura; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier

2014-01-01

Dendritic spines establish most excitatory synapses in the brain and are located in Purkinje cell's dendrites along helical paths, perhaps maximizing the probability to contact different axons. To test whether spine helixes also occur in neocortex, we reconstructed >500 dendritic segments from adult human cortex obtained from autopsies. With Fourier analysis and spatial statistics, we analyzed spine position along apical and basal dendrites of layer 3 pyramidal neurons from frontal, temporal, and cingulate cortex. Although we occasionally detected helical positioning, for the great majority of dendrites we could not reject the null hypothesis of spatial randomness in spine locations, either in apical or basal dendrites, in neurons of different cortical areas or among spines of different volumes and lengths. We conclude that in adult human neocortex spine positions are mostly random. We discuss the relevance of these results for spine formation and plasticity and their functional impact for cortical circuits. PMID:25057209

Random positions of dendritic spines in human cerebral cortex.

PubMed

Morales, Juan; Benavides-Piccione, Ruth; Dar, Mor; Fernaud, Isabel; Rodríguez, Angel; Anton-Sanchez, Laura; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier; Yuste, Rafael

2014-07-23

Dendritic spines establish most excitatory synapses in the brain and are located in Purkinje cell's dendrites along helical paths, perhaps maximizing the probability to contact different axons. To test whether spine helixes also occur in neocortex, we reconstructed >500 dendritic segments from adult human cortex obtained from autopsies. With Fourier analysis and spatial statistics, we analyzed spine position along apical and basal dendrites of layer 3 pyramidal neurons from frontal, temporal, and cingulate cortex. Although we occasionally detected helical positioning, for the great majority of dendrites we could not reject the null hypothesis of spatial randomness in spine locations, either in apical or basal dendrites, in neurons of different cortical areas or among spines of different volumes and lengths. We conclude that in adult human neocortex spine positions are mostly random. We discuss the relevance of these results for spine formation and plasticity and their functional impact for cortical circuits. Copyright © 2014 the authors 0270-6474/14/3410078-07$15.00/0.

Eliminating log rolling as a spine trauma order.

PubMed

Conrad, Bryan P; Rossi, Gianluca Del; Horodyski, Mary Beth; Prasarn, Mark L; Alemi, Yara; Rechtine, Glenn R

2012-01-01

Currently, up to 25% of patients with spinal cord injuries may experience neurologic deterioration during the initial management of their injuries. Therefore, more effective procedures need to be established for the transportation and care of these to reduce the risk of secondary neurologic damage. Here, we present more acceptable methods to minimize motion in the unstable spine during the management of patients with traumatic spine injuries. This review summarizes more than a decade of research aimed at evaluating different methods of caring for patients with spine trauma. The most commonly utilized technique to transport spinal cord injured patients, the log rolling maneuver, produced more motion than placing a patient on a spine board, removing a spine board, performing continuous lateral therapy, and positioning a patient prone for surgery. Alternative maneuvers that produced less motion included the straddle lift and slide, 6 + lift and slide, scoop stretcher, mechanical kinetic therapy, mechanical transfers, and the use of the operating table to rotate the patient to the prone position for surgical stabilization. The log roll maneuver should be removed from the trauma response guidelines for patients with suspected spine injuries, as it creates significantly more motion in the unstable spine than the readily available alternatives. The only exception is the patient who is found prone, in which case the patient should then be log rolled directly on to the spine board utilizing a push technique.

Seasonal patterns of weight, hematology, and serum characteristics of free-ranging female white-tailed deer in Minnesota

USGS Publications Warehouse

DelGiudice, G.D.; Mech, L.D.; Kunkel, K.E.; Gese, E.M.; Seal, U.S.

1992-01-01

Weights, hematology, and serum profIles of white-tailed does in the central Superior National Forest of northeastern Minnesota were examined year-around to determine seasonal patterns of nutritional condition and metabolism. Deer were initially captured by Clover trap or rocket net. Between 15 February 1989 and 23 January 1990, we recaptured 12 adult (> 1.5 years) female deer 1-9 times each (a total of 59 recaptures) using a radio-controlled capture collar. Monthly weights of deer exhibited a cyclic seasonal pattern. Mean weight declined 22 % from February to an annual minimum during May, then steadily increased 45 % to a maximum in October. Seasonal patterns were most evident for hemoglobin concentration, red blood cells, packed cell volume, serum total protein, urea nitrogen, creatinine, the urea N to creatinine ratio, triiodothyronine, cortisol, and potassium. Wide seasonal variations of these characteristics were indicative of shifts in the deer's metabolic physiology. Although seasonal metabolic shifts are partially attributable to an endogenous rhythm, the intensity of, their expression was most likely affected by nutritional changes and concomitant alterations of body condition. Annual changes in seasonal trends of blood characteristics may be useful in investigating nutritional effects of specific environmental and demographic factors. We compare our findings with those reported for deer on ranges farther south.

The effect of terrain and female density on survival of neonatal white-tailed deer and mule deer fawns.

PubMed

Bonar, Maegwin; Manseau, Micheline; Geisheimer, Justin; Bannatyne, Travis; Lingle, Susan

2016-07-01

Juvenile survival is a highly variable life-history trait that is critical to population growth. Antipredator tactics, including an animal's use of its physical and social environment, are critical to juvenile survival. Here, we tested the hypothesis that habitat and social characteristics influence coyote (Canis latrans) predation on white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus) fawns in similar ways during the neonatal period. This would contrast to winter when the habitat and social characteristics that provide the most safety for each species differ. We monitored seven cohorts of white-tailed deer and mule deer fawns at a grassland study site in Alberta, Canada. We used logistic regression and a model selection procedure to determine how habitat characteristics, climatic conditions, and female density influenced fawn survival during the first 8 weeks of life. Fawn survival improved after springs with productive vegetation (high integrated Normalized Difference Vegetation Index values). Fawns that used steeper terrain were more likely to survive. Fawns of both species had improved survival in years with higher densities of mule deer females, but not with higher densities of white-tailed deer females, as predicted if they benefit from protection by mule deer. Our results suggest that topographical variation is a critical resource for neonates of many ungulate species, even species like white-tailed deer that use more gentle terrain when older. Further, our results raise the possibility that neonatal white-tailed fawns may benefit from associating with mule deer females, which may contribute to the expansion of white-tailed deer into areas occupied by mule deer.

[Management of spine injuries in polytraumatized patients].

PubMed

Heyde, C E; Ertel, W; Kayser, R

2005-09-01

The management of spine injuries in polytraumatized patients remains a great challenge for the diagnostic procedures and institution of appropriate treatment by integrating spinal trauma treatment into the whole treatment concept as well as following the treatment steps for the injured spine itself. The established concept of "damage control" and criteria regarding the optimal time and manner for operative treatment of the injured spine in the polytrauma setting is presented and discussed.

Burst fractures of the lumbar spine in frontal crashes.

PubMed

Kaufman, Robert P; Ching, Randal P; Willis, Margaret M; Mack, Christopher D; Gross, Joel A; Bulger, Eileen M

2013-10-01

In the United States, major compression and burst type fractures (>20% height loss) of the lumbar spine occur as a result of motor vehicle crashes, despite the improvements in restraint technologies. Lumbar burst fractures typically require an axial compressive load and have been known to occur during a non-horizontal crash event that involve high vertical components of loading. Recently these fracture patterns have also been observed in pure horizontal frontal crashes. This study sought to examine the contributing factors that would induce an axial compressive force to the lumbar spine in frontal motor vehicle crashes. We searched the National Automotive Sampling System (NASS, 1993-2011) and Crash Injury Research and Engineering Network (CIREN, 1996-2012) databases to identify all patients with major compression lumbar spine (MCLS) fractures and then specifically examined those involved in frontal crashes. National trends were assessed based on weighted NASS estimates. Using a case-control study design, NASS and CIREN cases were utilized and a conditional logistic regression was performed to assess driver and vehicle characteristics. CIREN case studies and biomechanical data were used to illustrate the kinematics and define the mechanism of injury. During the study period 132 NASS cases involved major compression lumbar spine fractures for all crash directions. Nationally weighted, this accounted for 800 cases annually with 44% of these in horizontal frontal crashes. The proportion of frontal crashes resulting in MCLS fractures was 2.5 times greater in late model vehicles (since 2000) as compared to 1990s models. Belted occupants in frontal crashes had a 5 times greater odds of a MCLS fracture than those not belted, and an increase in age also greatly increased the odds. In CIREN, 19 cases were isolated as horizontal frontal crashes and 12 of these involved a major compression lumbar burst fracture primarily at L1. All were belted and almost all occurred in late

TIDAL TAILS OF MINOR MERGERS. II. COMPARING STAR FORMATION IN THE TIDAL TAILS OF NGC 2782

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knierman, Karen A.; Scowen, Paul; Veach, Todd

2013-09-10

The peculiar spiral NGC 2782 is the result of a minor merger with a mass ratio {approx}4: 1 occurring {approx}200 Myr ago. This merger produced a molecular and H I-rich, optically bright eastern tail and an H I-rich, optically faint western tail. Non-detection of CO in the western tail by Braine et al. suggested that star formation had not yet begun. However, deep UBVR and H{alpha} narrowband images show evidence of recent star formation in the western tail, though it lacks massive star clusters and cluster complexes. Using Herschel PACS spectroscopy, we discover 158 {mu}m [C II] emission at themore » location of the three most luminous H{alpha} sources in the eastern tail, but not at the location of the even brighter H{alpha} source in the western tail. The western tail is found to have a normal star formation efficiency (SFE), but the eastern tail has a low SFE. The lack of CO and [C II] emission suggests that the western tail H II region may have a low carbon abundance and be undergoing its first star formation. The western tail is more efficient at forming stars, but lacks massive clusters. We propose that the low SFE in the eastern tail may be due to its formation as a splash region where gas heating is important even though it has sufficient molecular and neutral gas to make massive star clusters. The western tail, which has lower gas surface density and does not form high-mass star clusters, is a tidally formed region where gravitational compression likely enhances star formation.« less

Visualization of scoliotic spine using ultrasound-accessible skeletal landmarks

NASA Astrophysics Data System (ADS)

Church, Ben; Lasso, Andras; Schlenger, Christopher; Borschneck, Daniel P.; Mousavi, Parvin; Fichtinger, Gabor; Ungi, Tamas

2017-03-01

PURPOSE: Ultrasound imaging is an attractive alternative to X-ray for scoliosis diagnosis and monitoring due to its safety and inexpensiveness. The transverse processes as skeletal landmarks are accessible by means of ultrasound and are sufficient for quantifying scoliosis, but do not provide an informative visualization of the spine. METHODS: We created a method for visualization of the scoliotic spine using a 3D transform field, resulting from thin-spline interpolation of a landmark-based registration between the transverse processes that we localized in both the patient's ultrasound and an average healthy spine model. Additional anchor points were computationally generated to control the thin-spline interpolation, in order to gain a transform field that accurately represents the deformation of the patient's spine. The transform field is applied to the average spine model, resulting in a 3D surface model depicting the patient's spine. We applied ground truth CT from pediatric scoliosis patients in which we reconstructed the bone surface and localized the transverse processes. We warped the average spine model and analyzed the match between the patient's bone surface and the warped spine. RESULTS: Visual inspection revealed accurate rendering of the scoliotic spine. Notable misalignments occurred mainly in the anterior-posterior direction, and at the first and last vertebrae, which is immaterial for scoliosis quantification. The average Hausdorff distance computed for 4 patients was 2.6 mm. CONCLUSIONS: We achieved qualitatively accurate and intuitive visualization to depict the 3D deformation of the patient's spine when compared to ground truth CT.

Ionic Liquids with Symmetric Diether Tails: Bulk and Vacuum-Liquid Interfacial Structures.

PubMed

Hettige, Jeevapani J; Amith, Weththasinghage D; Castner, Edward W; Margulis, Claudio J

2017-01-12

The behavior in the bulk and at interfaces of biphilic ionic liquids in which either the cation or anion possesses moderately long alkyl tails is to a significant degree well understood. Less clear is what happens when both the cation and anion possess tails that are not apolar, such as in the case of ether functionalities. The current article discusses the structural characteristics of C2OC2OC2-mim + /C2OC2OC2-OSO 3 - in the bulk and at the vacuum interface. We find that the vacuum interface affects only the nanometer length scale. This is in contrast to what we have recently found in ( J. Phys. Chem. Lett. , 2016 , 7 ( 19 ), 3785 - -3790 ) for isoelectronic C[8]-mim + /C[8]-OSO 3 - , where the interface effect is long ranged. Interestingly, ions with the diether tail functionality still favor the tail-outward orientation at the vacuum interface and the bulk phase preserves the alternation between charged networks and tails that is commonly observed for biphilic ionic liquids. However, such alternation is less well-defined and results in a significantly diminished first sharp diffraction peak in the bulk liquid structure function.

On the large-scale structure of the tail current as measured by THEMIS

NASA Astrophysics Data System (ADS)

Kalegaev, V. V.; Alexeev, I. I.; Nazarkov, I. S.; Angelopoulos, V.; Runov, A.

2014-11-01

The magnetic field structure and the spatial characteristics of the large-scale currents in the magnetospheric tail were studied during quiet and moderately disturbed geomagnetic conditions in 2009. The magnetic field of the currents other than the tail current was calculated in terms of a paraboloid model of the Earth’s magnetosphere, A2000, and was subtracted from measurements. It was found on the base of obtained tail current magnetic field radial distribution that the inner edge of the tail current sheet is located in the night side magnetosphere, at distances of about 10 RE and of about 7 RE during quiet and disturbed periods respectively. During the disturbance of February 14, 2009 (Dstmin ∼ -35 nT), the Bx and the Bz component of the tail current magnetic field near its inner edge were about 60 nT, and -60 nT that means that strong cross-tail current have been developed. The tail current parameters at different time moments during February 14, 2009 have been estimated. Solar wind conditions during this event were consistent with those during moderate magnetic storms with minimum Dst of about -100 nT. However, the magnetospheric current systems (magnetopause and cross-tail currents) were located at larger geocentric distances than typical during the 2009 extremely quiet epoch and did not provide the expected Dst magnitude. Very small disturbance on the Earth’s surface was detected consistent with an “inflated” magnetosphere.

THE NARROW X-RAY TAIL AND DOUBLE Hα TAILS OF ESO 137-002 IN A3627

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, B.; Lin, X. B.; Kong, X.

2013-11-10

We present the analysis of a deep Chandra observation of a ∼2 L{sub *} late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (∼>40 kpc) and narrow tail with a nearly constant width (∼3 kpc) to the southeast of the galaxy, and a leading edge ∼1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's interstellar medium (ISM) by ram pressure, compared to the nearly face-on stripping of ESO 137-001 discussed in our previous work. Spectralmore » analysis of individual regions along the tail shows that the gas throughout it has a rather constant temperature, ∼1 keV, very close to the temperature of the tails of ESO 137-001, if the same atomic database is used. The derived gas abundance is low (∼0.2 solar with the single-kT model), an indication of the multiphase nature of the gas in the tail. The mass of the X-ray tail is only a small fraction (<5%) of the initial ISM mass of the galaxy, suggesting that the stripping is most likely at an early stage. However, with any of the single-kT, double-kT, and multi-kT models we tried, the tail is always 'over-pressured' relative to the surrounding intracluster medium (ICM), which could be due to the uncertainties in the abundance, thermal versus non-thermal X-ray emission, or magnetic support in the ICM. The Hα data from the Southern Observatory for Astrophysical Research show a ∼21 kpc tail spatially coincident with the X-ray tail, as well as a secondary tail (∼12 kpc long) to the east of the main tail diverging at an angle of ∼23° and starting at a distance of ∼7.5 kpc from the nucleus. At the position of the secondary Hα tail, the X-ray emission is also enhanced at the ∼2σ level. We compare the tails of ESO 137-001 and ESO 137-002, and also compare the tails to simulations. Both the similarities and differences of the tails pose challenges to the simulations. Several

Remote Sensing Extraction of Stopes and Tailings Ponds in AN Ultra-Low Iron Mining Area

NASA Astrophysics Data System (ADS)

Ma, B.; Chen, Y.; Li, X.; Wu, L.

2018-04-01

With the development of economy, global demand for steel has accelerated since 2000, and thus mining activities of iron ore have become intensive accordingly. An ultra-low-grade iron has been extracted by open-pit mining and processed massively since 2001 in Kuancheng County, Hebei Province. There are large-scale stopes and tailings ponds in this area. It is important to extract their spatial distribution information for environmental protection and disaster prevention. A remote sensing method of extracting stopes and tailings ponds is studied based on spectral characteristics by use of Landsat 8 OLI imagery and ground spectral data. The overall accuracy of extraction is 95.06 %. In addition, tailings ponds are distinguished from stopes based on thermal characteristics by use of temperature image. The results could provide decision support for environmental protection, disaster prevention, and ecological restoration in the ultra-low-grade iron ore mining area.

Automatic early warning of tail biting in pigs: 3D cameras can detect lowered tail posture before an outbreak

PubMed Central

Jack, Mhairi; Futro, Agnieszka; Talbot, Darren; Zhu, Qiming; Barclay, David; Baxter, Emma M.

2018-01-01

Tail biting is a major welfare and economic problem for indoor pig producers worldwide. Low tail posture is an early warning sign which could reduce tail biting unpredictability. Taking a precision livestock farming approach, we used Time-of-flight 3D cameras, processing data with machine vision algorithms, to automate the measurement of pig tail posture. Validation of the 3D algorithm found an accuracy of 73.9% at detecting low vs. not low tails (Sensitivity 88.4%, Specificity 66.8%). Twenty-three groups of 29 pigs per group were reared with intact (not docked) tails under typical commercial conditions over 8 batches. 15 groups had tail biting outbreaks, following which enrichment was added to pens and biters and/or victims were removed and treated. 3D data from outbreak groups showed the proportion of low tail detections increased pre-outbreak and declined post-outbreak. Pre-outbreak, the increase in low tails occurred at an increasing rate over time, and the proportion of low tails was higher one week pre-outbreak (-1) than 2 weeks pre-outbreak (-2). Within each batch, an outbreak and a non-outbreak control group were identified. Outbreak groups had more 3D low tail detections in weeks -1, +1 and +2 than their matched controls. Comparing 3D tail posture and tail injury scoring data, a greater proportion of low tails was associated with more injured pigs. Low tails might indicate more than just tail biting as tail posture varied between groups and over time and the proportion of low tails increased when pigs were moved to a new pen. Our findings demonstrate the potential for a 3D machine vision system to automate tail posture detection and provide early warning of tail biting on farm. PMID:29617403

Dendritic spine dysgenesis in Rett syndrome

PubMed Central

Xu, Xin; Miller, Eric C.; Pozzo-Miller, Lucas

2014-01-01

Spines are small cytoplasmic extensions of dendrites that form the postsynaptic compartment of the majority of excitatory synapses in the mammalian brain. Alterations in the numerical density, size, and shape of dendritic spines have been correlated with neuronal dysfunction in several neurological and neurodevelopmental disorders associated with intellectual disability, including Rett syndrome (RTT). RTT is a progressive neurodevelopmental disorder associated with intellectual disability that is caused by loss of function mutations in the transcriptional regulator methyl CpG-binding protein 2 (MECP2). Here, we review the evidence demonstrating that principal neurons in RTT individuals and Mecp2-based experimental models exhibit alterations in the number and morphology of dendritic spines. We also discuss the exciting possibility that signaling pathways downstream of brain-derived neurotrophic factor (BDNF), which is transcriptionally regulated by MeCP2, offer promising therapeutic options for modulating dendritic spine development and plasticity in RTT and other MECP2-associated neurodevelopmental disorders. PMID:25309341

Intravertebral pneumatocysts of the cervical spine.

PubMed

Matsukubo, Yuko; Kashiwagi, Nobuo; Uemura, Masanobu; Tatsumi, Sachiyo; Takahashi, Hiroto; Hyodo, Tomoko; Tomiyama, Noriyuki; Ashikaga, Ryuichiro; Ishii, Kazunari; Murakami, Takamichi

2013-11-01

The aim of this study was to investigate the prevalence of intravertebral pneumatocyst (IVP) of the cervical spine by age group, compared with that of intradiscal vacuum (IDV). We investigated 500 consecutive patients who underwent cervical computed tomography (CT) from May 2012 to May 2013 for various indications. CT datasets were assessed for the presence of IVPs and IDVs with stratification by age. IVPs of the cervical spine were detected in 8 % (7 of 86 subjects) of patients in their forties or below, 30 % (23 of 75) in their fifties, 49 % (67 of 136) in their sixties, 55 % (76 of 137) in their seventies, and 60 % (40 of 66) in their eighties or over. IDVs of the cervical spine were detected in 6, 25, 48, 54, and 57 %, respectively. Coexistence of both phenomena was identified in 4, 17, 33, 40, and 43 %, respectively. IVPs of the cervical spine are a common incidental finding, increasing in prevalence with age and more common than IDV in all age groups.

Surgery for failed cervical spine reconstruction.

PubMed

Helgeson, Melvin D; Albert, Todd J

2012-03-01

Review article. To review the indications, operative strategy, and complications of revision cervical spine reconstruction. With many surgeons expanding their indications for cervical spine surgery, the number of patients being treated operatively has increased. Unfortunately, the number of patients requiring revision procedures is also increasing, but very little literature exists reviewing changes in the indications or operative planning for revision reconstruction. Narrative and review of the literature. In addition to the well-accepted indications for primary cervical spine surgery (radiculopathy, myelopathy, instability, and tumor), we have used the following indications for revision surgery: pseudarthrosis, adjacent segment degeneration, inadequate decompression, iatrogenic instability, and deformity. Our surgical goal for pseudarthrosis is obviously to obtain a fusion, which can usually be performed with an approach not done previously. Our surgical goals for instability and deformity are more complex, with a focus on decompression of any neurologic compression, correction of deformity, and stability. Revision cervical spine reconstruction is safe and effective if performed for the appropriate indications and with proper planning.

Marble wastes and pig slurry improve the environmental and plant-relevant properties of mine tailings.

PubMed

Kabas, S; Faz, A; Acosta, J A; Arocena, J M; Zornoza, R; Martínez-Martínez, S; Carmona, D M

2014-02-01

Poor soil fertility is often the biggest challenge to the establishment of vegetation in mine wastes deposits. We conducted field trials in the El Gorguel and El Lirio sites in SE Spain, two representative tailing ponds of similar properties except for pH, to understand the environmental and plant-relevant benefits of marble waste (MW) and pig slurry (PS) applications to mine tailings. Low pH (5.4) tailings (El Lirio) exhibit reduction of up to fourfold in bio-availability of metals as shown by the DTPA-Zn, Pb, water-soluble Zn, Pb and up to 3× for water-soluble Cd. Tailings in El Gorguel have high pH (7.4) and did not exhibit significant trends in the reductions of water-extractable Zn, Pb, Cd and Cu. Improvements to the edaphic (plant-relevant) properties of tailings after the amendments are not as sensitive to pH compared to the environmental characteristics. The two sites had increases in aggregate stability, organic matter (total N and organic C) although total N is higher in the El Gorguel (up to 212 μg N kg(-1)) than the El Lirio (up to 26 μg N kg(-1)). However, cation exchange capacities are similar in both sites at 15.2 cmol(+) kg(-1). We conclude that the characteristics, especially pH, of tailing materials significantly influence the fate of metals but not improvements to plant-relevant properties such as cation exchange capacity and aggregate stability 1 year after the application of MW and PS amendments.

Micromechanics of Sea Urchin Spines

PubMed Central

Tsafnat, Naomi; Fitz Gerald, John D.; Le, Hai N.; Stachurski, Zbigniew H.

2012-01-01

The endoskeletal structure of the Sea Urchin, Centrostephanus rodgersii, has numerous long spines whose known functions include locomotion, sensing, and protection against predators. These spines have a remarkable internal microstructure and are made of single-crystal calcite. A finite-element model of the spine’s unique porous structure, based on micro-computed tomography (microCT) and incorporating anisotropic material properties, was developed to study its response to mechanical loading. Simulations show that high stress concentrations occur at certain points in the spine’s architecture; brittle cracking would likely initiate in these regions. These analyses demonstrate that the organization of single-crystal calcite in the unique, intricate morphology of the sea urchin spine results in a strong, stiff and lightweight structure that enhances its strength despite the brittleness of its constituent material. PMID:22984468

Activity-dependent dendritic spine neck changes are correlated with synaptic strength

PubMed Central

Araya, Roberto; Vogels, Tim P.; Yuste, Rafael

2014-01-01

Most excitatory inputs in the mammalian brain are made on dendritic spines, rather than on dendritic shafts. Spines compartmentalize calcium, and this biochemical isolation can underlie input-specific synaptic plasticity, providing a raison d’etre for spines. However, recent results indicate that the spine can experience a membrane potential different from that in the parent dendrite, as though the spine neck electrically isolated the spine. Here we use two-photon calcium imaging of mouse neocortical pyramidal neurons to analyze the correlation between the morphologies of spines activated under minimal synaptic stimulation and the excitatory postsynaptic potentials they generate. We find that excitatory postsynaptic potential amplitudes are inversely correlated with spine neck lengths. Furthermore, a spike timing-dependent plasticity protocol, in which two-photon glutamate uncaging over a spine is paired with postsynaptic spikes, produces rapid shrinkage of the spine neck and concomitant increases in the amplitude of the evoked spine potentials. Using numerical simulations, we explore the parameter regimes for the spine neck resistance and synaptic conductance changes necessary to explain our observations. Our data, directly correlating synaptic and morphological plasticity, imply that long-necked spines have small or negligible somatic voltage contributions, but that, upon synaptic stimulation paired with postsynaptic activity, they can shorten their necks and increase synaptic efficacy, thus changing the input/output gain of pyramidal neurons. PMID:24982196

Nesting habitat relationships of sympatric Crested Caracaras, Red-tailed Hawks, and White-tailed Hawks in South Texas

USGS Publications Warehouse

Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

2007-01-01

We quantified nesting-site habitats for sympatric White-tailed Hawks (Buteo albicaudatus) (n = 40), Red-tailed Hawks (B. jamaicensis) (n = 39), and Crested Caracaras (Caracara cheriway) (n = 24) in the Coastal Sand Plain of south Texas. White-tailed Hawks and Crested Caracara nest sites occurred in savannas, whereas Red-tailed Hawk nest sites occurred in woodlands on the edge of savannas. White-tailed Hawk nest sites were in shrubs and trees that were shorter (3.5 ?? 1.0 m) and had smaller canopy diameters (5.5 ?? 2.1 m) than those of Red-tailed Hawks (10.1 ?? 2.0 m, 13.7 ?? 5.8 m) and Crested Caracaras (5.6 ?? 1.7 m, 8.5 ?? 3.5 m). Red-tailed Hawk nest sites had higher woody densities (15.7 ?? 9.6 plants) and more woody cover (84 ?? 19%) than those of White-tailed Hawks (5.6 ?? 5.8 plants, 20 ?? 21%) and Crested Caracaras (9.9 ?? 6.7 plants, 55 ?? 34%). Crested Caracara nest sites were in dense, multi-branched shrubs composed of more living material (97 ?? 3%) than those of White-tailed (88 ?? 18%) and Red-tailed hawks (88 ?? 18%). Nest sites of White-tailed Hawks, Red-tailed Hawks, and Crested Caracaras were similar to random samples from the surrounding habitat indicating that preferred nesting habitat was available for each of these species at least within 60 m of active nest sites. Nest tree height, along with woody plant and native grass cover best discriminated nest sites among the three raptor species. There was no overlap at Red-tailed and White-tailed hawk nest sites in vegetation structure, while Crested Caracara nests were in habitat intermediate between the two other species. Partitioning of nesting habitat may be how these raptor species co-exist at the broader landscape scale of our study area in the Coastal Sand Plain of Texas.

Imaging evaluation of traumatic thoracolumbar spine injuries: Radiological review

PubMed Central

Gamanagatti, Shivanand; Rathinam, Deepak; Rangarajan, Krithika; Kumar, Atin; Farooque, Kamran; Sharma, Vijay

2015-01-01

Spine fractures account for a large portion of musculoskeletal injuries worldwide. A classification of spine fractures is necessary in order to develop a common language for treatment indications and outcomes. Several classification systems have been developed based on injury anatomy or mechanisms of action, but they have demonstrated poor reliability, have yielded little prognostic information, and have not been widely used. For this reason, the Arbeitsgemeinschaftfür Osteosynthesefragen (AO) committee has classified thorocolumbar spine injuries based on the pathomorphological criteria into3 types (A: Compression; B: Distraction; C: Axial torque and rotational deformity). Each of these types is further divided into 3 groups and 3 subgroups reflecting progressive scale of morphological damage and the degree of instability. Because of its highly detailed sub classifications, the AO system has shown limited interobserver variability. It is similar to its predecessors in that it does not incorporate the patient’s neurologic status.The need for a reliable, reproducible, clinically relevant, prognostic classification system with an optimal balance of ease of use and detail of injury description contributed to the development of a new classification system, the thoracolumbar injury classification and severity score (TLICS). The TLICS defines injury based on three clinical characteristics: injury morphology, integrity of the posterior ligamentous complex, and neurologic status of the patient. The severity score offers prognostic information and is helpful in decision making about surgical vs nonsurgical management. PMID:26435776

Three new endemic species of Epictia Gray, 1845 (Serpentes: Leptotyphlopidae) from the dry forest of northwestern Peru.

PubMed

Koch, Claudia; Venegas, Pablo J; Böhme, Wolfgang

2015-06-02

Three new blind snake species of the genus Epictia are described based on material collected in the Peruvian Regions Amazonas, Cajamarca and La Libertad. All three species are well differentiated from all congeners based on characteristics of their morphology and coloration. They share 10 scale rows around the middle of the tail and possess two supralabials with the anterior one in broad contact with the supraocular. Epictia septemlineata sp. nov. has 16 subcaudal scales, 257 mid-dorsal scale rows, a yellowish-white rostral, and a black terminal spine. Epictia vanwallachi sp. nov. exhibits 16 subcaudals, 188 mid-dorsal scale rows, a grayish-brown rostral, and a yellow terminal spine. Epictia antoniogarciai sp. nov. features 14-18 subcaudals, 195-208 mid-dorsal scale rows, a bright yellow or yellowish-white rostral, and the terminal spine and terminal portion of the tail yellow. All three species were collected in the interandean dry forest valleys of the Marañón River and its tributaries. This region is an area of endemism and warrants further attention from systematic and conservation biologists.

Aerodynamic Characteristics of a Refined Deep-step Planing-tail Flying-boat Hull with Various Forebody and Afterbody Shapes

NASA Technical Reports Server (NTRS)

Riebe, John M; Naeseth, Rodger L

1952-01-01

An investigation was made in the Langley 300-mph 7- by 10-foot tunnel to determine the aerodynamic characteristics of a refined deep-step planing-tail hull with various forebody and afterbody shapes and, for comparison, a streamline body simulating the fuselage of a modern transport airplane. The results of the tests indicated that the configurations incorporating a forebody with a length-beam ratio of 7 had lower minimum drag coefficients than the configurations incorporating a forebody with length-beam ratio of 5. The lowest minimum drag coefficients, which were considerably less than that of a conventional hull and slightly less than that of a streamline body, were obtained on the length-beam-ratio-7 forebody, alone and with round center boom. Drag coefficients and longitudinal- and lateral-stability parameters presented include the interference of a 21-percent-thick support wing.

Does football cause an increase in degenerative disease of the lumbar spine?

PubMed

Gerbino, Peter G; d'Hemecourt, Pierre A

2002-02-01

Degenerative disease of the lumbar spine is exceedingly common. Whether any specific activity increases the likelihood of developing degenerative disc disease (DDD) or facet degeneration (FD) has enormous implications. Within the field of occupational medicine there are specific activities, occupations, and morphologic characteristics that have been related to low back pain. Several specific risk factors have been conclusively linked to low back pain, and in particular DDD and FD. Within the sport of American football, there has long been the feeling that many athletes have or will develop low back pain, DDD, and FD. Proving that certain risk factors present in football will predictably lead to an increase in LBP, DDD, and FD is more difficult. At this time, it can be said that football players, in general, increase their risk of developing low back pain, DDD, and FD as their years of involvement with their sport increase. Because specific spine injuries like fracture, disc herniation, and spondylolysis are more frequent in football players, the resulting DDD and FD are greater than that of the general population. The weightlifting and violent hyperextension that are part of American football are independent risk factors for degenerative spine disease.

A direct comparison of spine rotational stiffness and dynamic spine stability during repetitive lifting tasks.

PubMed

Graham, Ryan B; Brown, Stephen H M

2012-06-01

Stability of the spinal column is critical to bear loads, allow movement, and at the same time avoid injury and pain. However, there has been a debate in recent years as to how best to define and quantify spine stability, with the outcome being that different methods are used without a clear understanding of how they relate to one another. Therefore, the goal of the present study was to directly compare lumbar spine rotational stiffness, calculated with an EMG-driven biomechanical model, to local dynamic spine stability calculated using Lyapunov analyses of kinematic data, during a series of continuous dynamic lifting challenges. Twelve healthy male subjects performed 30 repetitive lifts under three varying load and three varying rate conditions. With an increase in the load lifted (constant rate) there was a significant increase in mean, maximum, and minimum spine rotational stiffness (p<0.001) and a significant increase in local dynamic stability (p<0.05); both stability measures were moderately to strongly related to one another (r=-0.55 to -0.71). With an increase in lifting rate (constant load), there was also a significant increase in mean and maximum spine rotational stiffness (p<0.01); however, there was a non-significant decrease in the minimum rotational stiffness and a non-significant decrease in local dynamic stability (p>0.05). Weak linear relationships were found for the varying rate conditions (r=-0.02 to -0.27). The results suggest that spine rotational stiffness and local dynamic stability are closely related to one another, as they provided similar information when movement rate was controlled. However, based on the results from the changing lifting rate conditions, it is evident that both models provide unique information and that future research is required to completely understand the relationship between the two models. Using both techniques concurrently may provide the best information regarding the true effects of (in) stability under

49 CFR 572.115 - Lumbar spine and pelvis.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for the lumbar spine and pelvis are identical to those for the SID dummy as set forth in § 572.42 except that the...

49 CFR 572.115 - Lumbar spine and pelvis.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for the lumbar spine and pelvis are identical to those for the SID dummy as set forth in § 572.42 except that the...

49 CFR 572.115 - Lumbar spine and pelvis.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for the lumbar spine and pelvis are identical to those for the SID dummy as set forth in § 572.42 except that the...

49 CFR 572.115 - Lumbar spine and pelvis.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for the lumbar spine and pelvis are identical to those for the SID dummy as set forth in § 572.42 except that the...

49 CFR 572.115 - Lumbar spine and pelvis.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Lumbar spine and pelvis. 572.115 Section 572.115... 50th Percentile Male § 572.115 Lumbar spine and pelvis. The specifications and test procedure for the lumbar spine and pelvis are identical to those for the SID dummy as set forth in § 572.42 except that the...

Pioneer 7 observations of plasma flow and field reversal regions in the distant geomagnetic tail

NASA Technical Reports Server (NTRS)

Walker, R. C.; Lazarus, A. J.; Villante, U.

1975-01-01

The present paper gives the results of an extensive analysis of plasma and magnetic-field data from Pioneer 7 taken in the geomagnetic tail approximately 1000 earth radii downstream from earth. The principal observations are: (1) measurable fluxes of protons in the tail, flowing away from earth, sometimes with a double-peaked velocity distribution; (2) field reversal regions in which the field changes from radial to antiradial by a vector rotation in the north-south plane; and (3) general characteristics of the tail similar to those observed near earth with good correlation between taillike magnetic fields and plasma.

Return to golf after spine surgery.

PubMed

Abla, Adib A; Maroon, Joseph C; Lochhead, Richard; Sonntag, Volker K H; Maroon, Adara; Field, Melvin

2011-01-01

no published evidence indicates when patients can resume golfing after spine surgery. The objective of this study is to provide data from surveys sent to spine surgeons. a survey of North American Spine Society members was undertaken querying the suggested timing of return to golf. Of 1000 spine surgeons surveyed, 523 responded (52.3%). The timing of recommended return to golf and the reasons were questioned for college/professional athletes and avid and recreational golfers of both sexes. Responses were tallied for lumbar laminectomy, lumbar microdiscectomy, lumbar fusion, and anterior cervical discectomy with fusion. the most common recommended time for return to golf was 4-8 weeks after lumbar laminectomy and lumbar microdiscectomy, 2-3 months after anterior cervical fusion, and 6 months after lumbar fusion. The results showed a statistically significant increase in the recommended time to resume golf after lumbar fusion than after cervical fusion in all patients (p < 0.01). The same holds true for the return to play after cervical fusion compared with either lumbar laminectomy or lumbar microdiscectomy for all golfer types (p < 0.01). There was a statistically significant shorter recommended time for professional and college golfers compared with noncompetitive golfers after lumbar fusion (p < 0.01), anterior cervical discectomy and fusion (p < 0.01), and lumbar microdiscectomy (p < 0.01). the return to golf after spine surgery depends on many variables, including the general well-being of patients in terms of pain control and comfort when golfing. This survey serves as a guide that can assist medical practitioners in telling patients the average times recommended by surgeons across North America regarding return to golf after spine surgery.

Tail Buffeting

NASA Technical Reports Server (NTRS)

Abdrashitov, G.

1943-01-01

An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.

Effect of spine motion on mobility in quadruped running

NASA Astrophysics Data System (ADS)

Chen, Dongliang; Liu, Qi; Dong, Litao; Wang, Hong; Zhang, Qun

2014-11-01

Most of current running quadruped robots have similar construction: a stiff body and four compliant legs. Many researches have indicated that the stiff body without spine motion is a main factor in limitation of robots' mobility. Therefore, investigating spine motion is very important to build robots with better mobility. A planar quadruped robot is designed based on cheetahs' morphology. There is a spinal driving joint in the body of the robot. When the spinal driving joint acts, the robot has spine motion; otherwise, the robot has not spine motion. Six group prototype experiments with the robot are carried out to study the effect of spine motion on mobility. In each group, there are two comparative experiments: the spinal driving joint acts in one experiment but does not in the other experiment. The results of the prototype experiments indicate that the average speeds of the robot with spine motion are 8.7%-15.9% larger than those of the robot without spine motion. Furthermore, a simplified sagittal plane model of quadruped mammals is introduced. The simplified model also has a spinal driving joint. Using a similar process as the prototype experiments, six group simulation experiments with the simplified model are conducted. The results of the simulation experiments show that the maximum rear leg horizontal thrusts of the simplified mode with spine motion are 68.2%-71.3% larger than those of the simplified mode without spine motion. Hence, it is found that spine motion can increase the average running speed and the intrinsic reason of speed increase is the improvement of the maximum rear leg horizontal thrust.

Investigation of motorcyclist cervical spine trauma using HUMOS model.

PubMed

Sun, Jingchao; Rojas, Alban; Bertrand, Pierre; Petit, Yvan; Kraenzler, Reinhard; Arnoux, Pierre Jean

2012-09-01

With 16 percent of the total road user fatalities, motorcyclists represent the second highest rate of road fatalities in France after car occupants. Regarding road accidents, a large proportion of trauma was on the lower cervical spine. According to different clinical studies, it is postulated that the cervical spine fragility areas are located on the upper and lower cervical spine. In motorcycle crashes, impact conditions occur on the head segment with various orientations and impact directions, leading to a combination of rotations and compression. Hence, motorcyclist vulnerability was investigated considering many impact conditions. Using the human model for safety (HUMOS), a finite element model, this work aims to provide an evaluation of the cervical spine weaknesses based on an evaluation of injury mechanisms. This evaluation consisted of defining 2 injury risk factors (joint injury and bone fracture) using a design of experiment including various velocities, impact directions, and impact orientations. The results confirmed previously reported clinical and epidemiological work on the fragility of the lower cervical spine and the upper cervical spine segments. Joint injuries appeared before bone fractures on both the upper and lower cervical spine. Bone fracture risk was greater on the lower cervical spine than on the upper cervical spine. The compression induced by a high impact angle was identified as an important injury severity factor. It significantly increased the injury incidence for both joint injuries and bone fractures. It also induced a shift in injury location from the lower to the upper cervical spine. The impact velocity exhibited a linear relationship with injury risks and severity. It also shifted the bone fracture risk from the lower to upper spinal segments.

Publication patterns of comparative effectiveness research in spine neurosurgery.

PubMed

Hueng, Dueng-Yuan; Tsai, Chia-Lin; Hsu, Shih-Wei; Ma, Hsin-I

2012-07-01

The purpose of this study was to investigate publication patterns for comparative effectiveness research (CER) on spine neurosurgery. The authors searched the PubMed database for the period 1980-2012 using the key words "cost analysis," "utility analysis," "cost-utility," "outcomes research," "practical clinical research," "comparator trial," and "comparative effectiveness research," linked with "effectiveness" and "spine neurosurgery." From 1980 through April 9, 2012, neurosurgery CER publications accounted for 1.38% of worldwide CER publications (8657 of 626,330 articles). Spine neurosurgery CER accounted for only 0.02%, with 132 articles. The journal with the greatest number of publications on spine neurosurgery CER was Spine, followed by the Journal of Neurosurgery: Spine. The average annual publication rate for spine neurosurgery CER during this period was 4 articles (132 articles in 33 years), with 68 (51.52%) of the 132 articles being published within the past 5 years and a rising trend beginning in 2008. The top 3 contributing countries were the US, Turkey, and Japan, with 68, 8, and 7 articles, respectively. Only 8 regular articles (6.06%) focused on cost analysis. There is a paucity of publications using CER methodology in spine neurosurgery. Few articles address the issue of cost analysis. The promotion of continuing medical education in CER methodology is warranted. Further investigations to address cost analysis in comparative effectiveness studies of spine neurosurgery are crucial to expand the application of CER in public health.

The robotic lumbar spine: dynamics and feedback linearization control.

PubMed

Karadogan, Ernur; Williams, Robert L

2013-01-01

The robotic lumbar spine (RLS) is a 15 degree-of-freedom, fully cable-actuated robotic lumbar spine which can mimic in vivo human lumbar spine movements to provide better hands-on training for medical students. The design incorporates five active lumbar vertebrae and the sacrum, with dimensions of an average adult human spine. It is actuated by 20 cables connected to electric motors. Every vertebra is connected to the neighboring vertebrae by spherical joints. Medical schools can benefit from a tool, system, or method that will help instructors train students and assess their tactile proficiency throughout their education. The robotic lumbar spine has the potential to satisfy these needs in palpatory diagnosis. Medical students will be given the opportunity to examine their own patient that can be programmed with many dysfunctions related to the lumbar spine before they start their professional lives as doctors. The robotic lumbar spine can be used to teach and test medical students in their capacity to be able to recognize normal and abnormal movement patterns of the human lumbar spine under flexion-extension, lateral bending, and axial torsion. This paper presents the dynamics and nonlinear control of the RLS. A new approach to solve for positive and nonzero cable tensions that are also continuous in time is introduced.

A sonographic approach to prenatal classification of congenital spine anomalies

PubMed Central

Robertson, Meiri; Sia, Sock Bee

2015-01-01

Abstract Objective: To develop a classification system for congenital spine anomalies detected by prenatal ultrasound. Methods: Data were collected from fetuses with spine abnormalities diagnosed in our institution over a five‐year period between June 2005 and June 2010. The ultrasound images were analysed to determine which features were associated with different congenital spine anomalies. Findings of the prenatal ultrasound images were correlated with other prenatal imaging, post mortem findings, post mortem imaging, neonatal imaging, karyotype, and other genetic workup. Data from published case reports of prenatal diagnosis of rare congenital spine anomalies were analysed to provide a comprehensive work. Results: During the study period, eighteen cases of spine abnormalities were diagnosed in 7819 women. The mean gestational age at diagnosis was 18.8w ± 2.2 SD. While most cases represented open NTD, a spectrum of vertebral abnormalities were diagnosed prenatally. These included hemivertebrae, block vertebrae, cleft or butterfly vertebrae, sacral agenesis, and a lipomeningocele. The most sensitive features for diagnosis of a spine abnormality included flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length. While reported findings at the time of diagnosis were often conservative, retrospective analysis revealed good correlation with radiographic imaging. 3D imaging was found to be a valuable tool in many settings. Conclusions: Analysis of the study findings showed prenatal ultrasound allowed detection of disruption to the normal appearances of the fetal spine. Using the three features of flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length, an algorithm was devised to aid with the diagnosis of spine anomalies for those who perform and report prenatal ultrasound. PMID:28191204

30-Day Readmission After Spine Surgery: An Analysis of 1400 Consecutive Spine Surgery Patients.

PubMed

Adogwa, Owoicho; Elsamadicy, Aladine A; Han, Jing L; Karikari, Isaac O; Cheng, Joseph; Bagley, Carlos A

2017-04-01

Retrospective cohort review. To identify the rates, causes, and risk factors for 30-day unplanned readmissions in after elective spine surgery at our institution. Early readmission after spine surgery is being used as a proxy for quality of care. One-fifth of patients are rehospitalized within 30 days after spine surgery. Nearly 60% of these readmissions are unplanned, which translates into billions of dollars in healthcare costs. A total of 1400 patients undergoing elective spine surgery at Duke University Hospital between 2008 and 2010 were included in the study. We identified all unplanned readmissions within 30 days of discharge. Unplanned readmissions were defined to have occurred as a result of either a surgical or a nonsurgical complication. Patient records were reviewed to determine the cause of readmission and the length of hospital stay. A total of 132 (9.4%) unplanned early readmissions were identified. The mean ± SD age was 58.6 ± 15.1 years. Lumbar decompression and fusion was the most common procedure The most common causes for readmission were infection or a concern for infection (34.8%) and pain (19.7%), and 26.5% of readmissions required a return to the operating room. The majority of patients that were readmitted presented to the emergency department from home (58.0%) whereas 25.2% were readmitted from a skilled nursing facility. The mean ± SD number of days from discharge to readmission was 9.8 ± 7.9 days and the average length of hospital stay for the readmissions was 7.5 days. This study suggests that infection and refractory pain were the most common primary reasons for unplanned readmission. Efforts at reducing unplanned early readmission after elective spine surgery should be focused on more effective post discharge care.

Comparison of Patient Outcomes and Cost of Overlapping Versus Nonoverlapping Spine Surgery.

PubMed

Zygourakis, Corinna C; Sizdahkhani, Saman; Keefe, Malla; Lee, Janelle; Chou, Dean; Mummaneni, Praveen V; Ames, Christopher P

2017-04-01

Overlapping surgery recently has gained significant media attention, but there are limited data on its safety and efficacy. To date, there has been no analysis of overlapping surgery in the field of spine. Our goal was to compare overlapping versus nonoverlapping spine surgery patient outcomes and cost. A retrospective review was undertaken of 2319 spine surgeries (n = 848 overlapping; 1471 nonoverlapping) performed by 3 neurosurgery attendings from 2012 to 2015 at the University of California San Francisco. Collected variables included patient age, sex, insurance, American Society of Anesthesiology score, severity of illness, risk of mortality, procedure type, surgeon, day of surgery, source of transfer, admission type, overlapping versus nonoverlapping surgery (≥1 minute of overlapping procedure time), Medicare-Severity Diagnosis-Related Group, osteotomy, and presence of another attending/fellow/resident. Univariate, then multivariate mixed-effect models were used to evaluate the effect of the collected variables on the following outcomes: procedure time, estimated blood loss, length of stay, discharge status, 30-day mortality, 30-day unplanned readmission, unplanned return to OR, and total hospital cost. Urgent spine cases were more likely to be done in an overlapping fashion (all P < 0.01). After we adjusted for patient demographics, clinical indicators, and procedure characteristics, overlapping surgeries had longer procedure times (estimate = 26.17; P < 0.001) and lower rates of discharge to home (odds ratio 0.65; P < 0.001), but equivalent rates of 30-day mortality, readmission, return to the operating room, estimated blood loss, length of stay, and total hospital cost (all P = ns). Overlapping spine surgery may be performed safely at our institution, although continued monitoring of patient outcomes is necessary. Overlapping surgery does not lead to greater hospital costs. Copyright © 2017 Elsevier Inc. All rights reserved.

Research on Long Tail Recommendation Algorithm

NASA Astrophysics Data System (ADS)

Hu, Xuezhi; Zhang, Chuang; Wu, Ming; Zeng, Yang

2017-10-01

Most recommendation systems in the major electronic commerce platforms are influenced by the long tail effect more or less. There are sufficient researches of how to assess recommendation effect while no criteria to evaluate long tail recommendation rate. In this study, we first discussed the existing problems of recommending long tail products through specific experiments. Then we proposed a long tail evaluation criteria and compared the performance in long tail recommendation between different models.

Survey of Hatching Spines of Bee Larvae Including Those of Apis mellifera (Hymenoptera: Apoidea).

PubMed

Rozen, Jerome G; Shepard Smith, Corey; Cane, James H

2017-07-01

This article explores the occurrence of hatching spines among bee taxa and how these structures enable a larva on hatching to extricate itself from the egg chorion. These spines, arranged in a linear sequence along the sides of the first instar just dorsal to the spiracles, have been observed and recorded in certain groups of solitary and cleptoparasitic bee taxa. After eclosion, the first instar remains loosely covered by the egg chorion. The fact that this form of eclosion has been detected in five families (Table 1 identifies four of the families. The fifth family is the Andrenidae for which the presence of hatching spines in the Oxaeinae will soon be announced.) of bees invites speculation as to whether it is a fundamental characteristic of bees, or at least of solitary and some cleptoparasitic bees. The wide occurrence of these spines has prompted the authors to explore and discover their presence in the highly eusocial Apis mellifera L. Hatching spines were indeed discovered on first instar A. mellifera. The honey bee hatching process appears to differ in that the spines are displayed somewhat differently though still along the sides of the body, and the chorion, instead of splitting along the sides of the elongate egg, seems to quickly disintegrate from the emerging first instar in association with the nearly simultaneous removal of the serosa that covers and separates the first instar from the chorion. Unexpected observations of spherical bodies of various sizes perhaps containing dissolving enzymes being discharged from spiracular openings during hatching may shed future light on the process of how A. mellifera effects chorion removal during eclosion. Whereas hatching spines occur among many groups of bees, they appear to be entirely absent in the Nomadinae and parasitic Apinae, an indication of a different eclosion process. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Cellular Therapy to Obtain Spine Fusion

DTIC Science & Technology

2012-07-01

competent and incompetent models the radio-micrographs show a distinct scoliosis in 6 month old growing mice, which received the Ad5BMP2 transduced cells...cells. Panel C, shows obvious curvature of the spine suggesting a significant scoliosis , as compared to the normal mouse spine, shown in panel B

Feasibility Studies on Pipeline Disposal of Concentrated Copper Tailings Slurry for Waste Minimization

NASA Astrophysics Data System (ADS)

Senapati, Pradipta Kumar; Mishra, Barada Kanta

2017-06-01

The conventional lean phase copper tailings slurry disposal systems create pollution all around the disposal area through seepage and flooding of waste slurry water. In order to reduce water consumption and minimize pollution, the pipeline disposal of these waste slurries at high solids concentrations may be considered as a viable option. The paper presents the rheological and pipeline flow characteristics of copper tailings samples in the solids concentration range of 65-72 % by weight. The tailings slurry indicated non-Newtonian behaviour at these solids concentrations and the rheological data were best fitted by Bingham plastic model. The influence of solids concentration on yield stress and plastic viscosity for the copper tailings samples were discussed. Using a high concentration test loop, pipeline experiments were conducted in a 50 mm nominal bore (NB) pipe by varying the pipe flow velocity from 1.5 to 3.5 m/s. A non-Newtonian Bingham plastic pressure drop model predicted the experimental data reasonably well for the concentrated tailings slurry. The pressure drop model was used for higher size pipes and the operating conditions for pipeline disposal of concentrated copper tailings slurry in a 200 mm NB pipe with respect to specific power consumption were discussed.

Start-up Characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources

NASA Astrophysics Data System (ADS)

Zhang, Renping

2017-12-01

A mathematical model was developed for predicting start-up characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources. The effects of heat capacitance of heat source, liquid-vapour interfacial evaporation-condensation heat transfer, shear stress at the interface was considered in current model. The interfacial evaporating mass flow rate is based on the kinetic analysis. Time variations of evaporating mass rate, wall temperature and liquid velocity are studied from the start-up to steady state. The calculated results show that wall temperature demonstrates step transition at the junction between the heat source and non-existent heat source on the evaporator. The liquid velocity changes drastically at the evaporator section, however, it has slight variation at the evaporator section without heat source. When the effect of heat source is ignored, the numerical temperature demonstrates a quicker response. With the consideration of capacitance of the heat source, the data obtained from the proposed model agree well with the experimental results.

A Tale of Tails: Dissecting the Enhancing Effect of Tailed Primers in Real-Time PCR

PubMed Central

Vandenbussche, Frank; Mathijs, Elisabeth; Lefebvre, David; De Clercq, Kris; Van Borm, Steven

2016-01-01

Non-specific tail sequences are often added to the 5’-terminus of primers to improve the robustness and overall performance of diagnostic assays. Despite the widespread use of tailed primers, the underlying working mechanism is not well understood. To address this problem, we conducted a detailed in vitro and in silico analysis of the enhancing effect of primer tailing on 2 well-established foot-and-mouth disease virus (FMDV) RT-qPCR assays using an FMDV reference panel. Tailing of the panFMDV-5UTR primers mainly affected the shape of the amplification curves. Modelling of the raw fluorescence data suggested a reduction of the amplification efficiency due to the accumulation of inhibitors. In depth analysis of PCR products indeed revealed the rapid accumulation of forward-primer derived artefacts. More importantly, tailing of the forward primer delayed artefacts formation and concomitantly restored the sigmoidal shape of the amplification curves. Our analysis also showed that primer tailing can alter utilisation patterns of degenerate primers and increase the number of primer variants that are able to participate in the reaction. The impact of tailed primers was less pronounced in the panFMDV-3D assay with only 5 out of 50 isolates showing a clear shift in Cq values. Sequence analysis of the target region of these 5 isolates revealed several mutations in the inter-primer region that extend an existing hairpin structure immediately downstream of the forward primer binding site. Stabilisation of the forward primer with either a tail sequence or cationic spermine units restored the sensitivity of the assay, which suggests that the enhancing effect in the panFMDV-3D assay is due to a more efficient extension of the forward primer. ur results show that primer tailing can alter amplification through various mechanisms that are determined by both the assay and target region. These findings expand our understanding of primer tailing and should enable a more targeted and

Loss of PSD-95 Enrichment is not a Prerequisite for Spine Retraction

PubMed Central

Woods, Georgia F.; Oh, Won Chan; Boudewyn, Lauren C.; Mikula, Sarah K.; Zito, Karen

2011-01-01

Changes in neuronal structure are thought to underlie long-term behavioral modifications associated with learning and memory. In particular, considerable evidence implicates the destabilization and retraction of dendritic spines along with the loss of spine synapses as an important cellular mechanism for refining brain circuits, yet the molecular mechanisms regulating spine elimination remain ill-defined. The postsynaptic density protein, PSD-95, is highly enriched in dendritic spines and has been associated with spine stability. Because spines with low levels of PSD-95 are more dynamic, and the recruitment of PSD-95 to nascent spines has been associated with spine stabilization, we hypothesized that loss of PSD-95 enrichment would be a prerequisite for spine retraction. To test this hypothesis, we used dual-color time-lapse two-photon microscopy to monitor rat hippocampal pyramidal neurons co-transfected with PSD-95-GFP and DsRed-Express, and we analyzed the relationship between PSD-95-GFP enrichment and spine morphological changes. Consistent with our hypothesis, we found that the majority of spines that retracted were relatively unenriched for PSD-95-GFP. However, in the subset of PSD-95-GFP-enriched spines that retracted, spine shrinkage and loss of PSD-95-GFP were tightly coupled, suggesting that loss of PSD-95-GFP enrichment did not precede spine retraction. Moreover, we found that in some instances spine retraction resulted in a significant enrichment of PSD-95-GFP on the dendritic shaft. Our data support a model of spine retraction in which loss of PSD-95 enrichment is not required prior to the destabilization of spines. PMID:21865455

Osteosarcoma of the mobile spine.

PubMed

Zils, K; Bielack, S; Wilhelm, M; Werner, M; Schwarz, R; Windhager, R; Hofmann-Wackersreuther, G; Andus, T; Kager, L; Kuehne, T; Reichardt, P; von Kalle, T

2013-08-01

The aims of this analysis were to investigate features and outcome of high-grade osteosarcomas of the mobile spine. Since 1977, 20 Cooperative Osteosarcoma Study Group patients had a diagnosis of high-grade osteosarcomas of the mobile spine and were included in this retrospective analysis of patient-, tumor- and treatment-related variables and outcome. The median age was 29 years (range 5-58). Most frequent tumor sites were thoracic and lumbar spine. All but three patients had nonmetastatic disease at diagnosis. Treatment included surgery and chemotherapy for all patients, 13 were also irradiated. Eight patients failed to achieve a macroscopically complete surgical remission (five local, one primary metastases, two both), six died, two are alive, both with radiotherapy. Of 12 patients with complete remission at all sites, three had a recurrence (two local, one metastases) and died. The median follow-up of the 11 survivors was 8.7 years (range 3.1-22.3), 5-year overall and event-free survival rates were 60% and 43%. Age <40 years, nonmetastatic disease at diagnosis and complete remission predicted for better overall survival (OS, P < 0.05). Osteosarcomas of the mobile spine are rare. With complete resection (and potentially radiotherapy) and chemotherapy, prognosis may be comparable with that of appendicular osteosarcomas.

Mineralogical and geochemical characterization of arsenic in an abandoned mine tailings of Korea.

PubMed

Ahn, Joo Sung; Park, Young Seog; Kim, Ju-Yong; Kim, Kyoung-Woong

2005-04-01

The mineralogical and chemical characteristics of As solid phases in arsenic-rich mine tailings from the Nakdong As-Bi mine in Korea was investigated. The tailings generated from the ore roasting process contained 4.36% of As whereas the concentration was up to 20.2% in some tailings from the cyanidation process for the Au extraction. Thin indurated layers and other secondary precipitates had formed at the surfaces of the tailings piles and the As contents of the hardened layers varied from 2.87 to 16.0%. Scorodite and iron arsenate (Fe3AsO7) were the primary As-bearing crystalline minerals. Others such as arsenolamprite, bernardite and titanium oxide arsenate were also found. The amorphous As-Fe phases often showed framboidal aggregates and gel type textures with desiccation cracks. Sequential extraction results also showed that 55.7-91.1% of the As in tailings were NH(4)-oxalate extractable As, further confirmed the predominance of amorphous As-Fe solid phases. When the tailings were equilibrated with de-ionized water, the solution exhibited extremely acidic conditions (pH 2.01-3.10) and high concentrations of dissolved As (up to 29.5 mg L(-1)), indicating high potentials for As to be released during rainfall events. The downstream water was affected by drainage from tailings and contained 12.7-522 microg L(-1) of As. The amorphous As-Fe phases in tailings have not entirely been stabilized through the long term natural weathering processes. To remediate the environmental harms they had caused, anthropogenic interventions to stabilize or immobilize As in the tailings pile should be explored.

Effectiveness of Treatment of Idiopathic Scoliosis by SpineCor Dynamic Bracing with Special Physiotherapy Programme in SpineCor System.

PubMed

Rożek, Karina; Potaczek, Tomasz; Zarzycka, Maja; Lipik, Ewa; Jasiewicz, Barbara

2016-10-28

The SpineCor dynamic brace for the treatment of idiopathic scoliosis is designed to maintain the correct position of the spine and a new movement strategy for 20 hours per day. The SpineCor exercise system intensifies and complements the brace treatment. This study evaluated the effectiveness of a comprehensive treatment of idiopathic scoliosis involving the SpineCor system. The study assessed a group of 40 patients (38 girls and 2 boys) with idiopathic scoliosis treated with the SpineCor brace. The average age at beginning of treatment was 13.1 yrs (10-15). Minimum treatment time was 18 months. 28 participants met the SRS criteria. Angles of the curve before and after bracing based on imaging studies were measured at the beginning and end of the treatment, analyzed and compared. Rehabilitation focused on teaching active corrective movement throughout the brace treatment. A control group was formed of 33 patients, including 21 meeting the SRS criteria, who used the SpineCor dynamic brace but did not participate in the associated exercise programme. Among patients from the exercise group who met the SRS criteria, 25% demonstrated reduced curve angles, 35.7% demonstrated curve progression and 39.3% showed stabilization (no change). Among patients meeting the SRS criteria from the control group, a decrease in curve angle was observed in 14.3% of the patients, curve progression in 57.1% and stabilization in 28.6%. 1. The addition of a dedicated physiotherapy programme to SpineCor dynamic bracing improves the chances of obtaining a positive outcome. 2. It is necessary to further analyse the course of the comprehensive treatment, also with regard to other types of braces and kinesiotherapy programmes.

Head and cervical spine posture in behaving rats: implications for modeling human conditions involving the head and cervical spine.

PubMed

Griffin, C; Choong, W Y; Teh, W; Buxton, A J; Bolton, P S

2015-02-01

The aim of this study was to define the temporal and spatial (postural) characteristics of the head and cervical vertebral column (spine) of behaving rats in order to better understand their suitability as a model to study human conditions involving the head and neck. Time spent in each of four behavioral postures was determined from video tape recordings of rats (n = 10) in the absence and presence of an intruder rat. Plain film radiographic examination of a subset of these rats (n = 5) in each of these postures allowed measurement of head and cervical vertebral column positions adopted by the rats. When single they were quadruped or crouched most (∼80%) of the time and bipedal either supported or free standing for only ∼10% of the time. The introduction of an intruder significantly (P < 0.0001) reduced the proportion of time rats spent quadruped (median, from 71% to 47%) and bipedal free standing (median, from 2.9% to 0.4%). The cervical spine was orientated (median, 25-75 percentile) near vertical (18.8°, 4.2°-30.9°) when quadruped, crouched (15.4°, 7.6°-69.3°) and bipedal supported (10.5°, 4.8°-22.6°) but tended to be less vertical oriented when bipedal free standing (25.9°, 7.7°-39.3°). The range of head positions relative to the cervical spine was largest when crouched (73.4°) and smallest when erect free standing (17.7°). This study indicates that, like humans, rats have near vertical orientated cervical vertebral columns but, in contrast to humans, they displace their head in space by movements at both the cervico-thoracic junction and the cranio-cervical regions. © 2014 Wiley Periodicals, Inc.

Visual loss after spine surgery: a population-based study.

PubMed

Patil, Chirag G; Lad, Eleonora M; Lad, Shivanand P; Ho, Chris; Boakye, Maxwell

2008-06-01

Retrospective cohort study using National inpatient sample administrative data. To determine national estimates of visual impairment and ischemic optic neuropathy after spine surgery. Loss of vision after spine surgery is rare but has devastating complications that has gained increasing recognition in the recent literature. National population-based studies of visual complications after spine surgery are lacking. All patients from 1993 to 2002 who underwent spine surgery (Clinical Classifications software procedure code: 3, 158) and who had ischemic optic neuropathy (ION) (ICD9-CM code 377.41), central retinal artery occlusion (CRAO) (ICD9-CM code 362.31) or non-ION, non-CRAO perioperative visual impairment (ICD9-CM codes: 369, 368.4, 368.8-9368.11-13) were included. Univariate and multivariate analysis were performed to identify potential risk factors. The overall incidence of visual disturbance after spine surgery was 0.094%. Spine surgery for scoliosis correction and posterior lumbar fusion had the highest rates of postoperative visual loss of 0.28% and 0.14% respectively. Pediatric patients (<18 years) were 5.8 times and elderly patients (>84 years) were 3.2 times more likely than, patients 18 to 44 years of age to develop non-ION, non-CRAO visual loss after spine surgery. Patients with peripheral vascular disease (OR = 2.0), hypertension (OR = 1.3), and those who received blood transfusion (OR = 2.2) were more likely to develop non-ION, non-CRAO vision loss after spine surgery. Ischemic optic neuropathy was present in 0.006% of patients. Hypotension (OR = 10.1), peripheral vascular disease (OR = 6.3) and anemia (OR = 5.9) were the strongest risk factors identified for the development of ION. We used multivariate analysis to identify significant risk factors for visual loss after spine surgery. National population-based estimate of visual impairment after spine surgery confirms that ophthalmic complications after spine surgery are rare. Since visual loss may be

Anatomical and morphological spine variation in Gymnocalycium kieslingii subsp. castaneum (Cactaceae)

PubMed Central

Gebauer, Roman; Řepka, Radomír; Šmudla, Radek; Mamoňová, Miroslava; Ďurkovič, Jaroslav

2016-01-01

Abstract Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp. castaneum (Ferrari) Slaba was analyzed. Fifteen plants were selected and from each plant one areole from the basal, middle and upper part of the plant body was sampled. A scanning electron microscopy was used for spine surface description and a light microscopy for measurements of spine width, thickness, cross-section area, fiber diameter and fiber cell wall thickness. The spine surface was more visible and damaged less in the upper part of the plant body than in the basal part. Large spine and fiber differences were found between upper and lower parts of the plant body, but also within single areoles. In general, the examined traits in the upper part had by 8–17% higher values than in the lower parts. The variation of spine and fiber traits within areoles was lower than the differences between individuals. The minimum sample size was largely influenced by the studied spine and fiber traits, ranging from 1 to 70 spines. The results provide pioneer information useful in spine sample collection in the field for taxonomical, biomechanical and structural studies. Nevertheless, similar studies should be carried out for other cacti species to make generalizations. The large spine and fiber variation within areoles observed in our study indicates a very complex spine morphogenesis. PMID:27698579

Anatomical and morphological spine variation in Gymnocalycium kieslingii subsp. castaneum (Cactaceae).

PubMed

Gebauer, Roman; Řepka, Radomír; Šmudla, Radek; Mamoňová, Miroslava; Ďurkovič, Jaroslav

2016-01-01

Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp. castaneum (Ferrari) Slaba was analyzed. Fifteen plants were selected and from each plant one areole from the basal, middle and upper part of the plant body was sampled. A scanning electron microscopy was used for spine surface description and a light microscopy for measurements of spine width, thickness, cross-section area, fiber diameter and fiber cell wall thickness. The spine surface was more visible and damaged less in the upper part of the plant body than in the basal part. Large spine and fiber differences were found between upper and lower parts of the plant body, but also within single areoles. In general, the examined traits in the upper part had by 8-17% higher values than in the lower parts. The variation of spine and fiber traits within areoles was lower than the differences between individuals. The minimum sample size was largely influenced by the studied spine and fiber traits, ranging from 1 to 70 spines. The results provide pioneer information useful in spine sample collection in the field for taxonomical, biomechanical and structural studies. Nevertheless, similar studies should be carried out for other cacti species to make generalizations. The large spine and fiber variation within areoles observed in our study indicates a very complex spine morphogenesis.

Dry needling for the management of thoracic spine pain

PubMed Central

Fernández-de-las-Peñas, César; Layton, Michelle; Dommerholt, Jan

2015-01-01

Thoracic spine pain is as disabling as neck and low back pain without receiving the same level of attention in the scientific literature. Among the different structures that can refer pain to the thoracic spine, muscles often play a relevant role. Trigger points (TrPs) from neck, shoulder and spinal muscles can induce pain in the region of the thoracic spine. There is a lack of evidence reporting the presence of TrPs in the region of the thoracic spine, but clinical evidence suggests that TrPs can be a potential source of thoracic spine pain. The current paper discusses the role of TrPs in the thoracic spine and dry needling (DN) for the management of TrPs in the thoracic multifidi and longissimus thoracis. This paper also includes a brief discussion of the application of DN in other tissues such as tendons, ligaments and scars. PMID:26309385

Aspergillus osteomyelitis of the spine.

PubMed

Govender, S; Rajoo, R; Goga, I E; Charles, R W

1991-07-01

Aspergillosis involving either the vertebral body or the intervertebral disc is a rare cause of osteomyelitis of the spine. The following is a report of five cases of Aspergillus fumigatus infection of the spine treated successfully with amphotericin B and 5-flucytosine. In three patients, the diagnosis was established at closed-needle biopsy; two patients with paraplegia had an anterior decompression and fusion. The follow-up period ranged from 19 to 48 months.

Runaway tails in magnetized plasmas

NASA Technical Reports Server (NTRS)

Moghaddam-Taaheri, E.; Vlahos, L.; Rowland, H. L.; Papadopoulos, K.

1985-01-01

The evolution of a runaway tail driven by a dc electric field in a magnetized plasma is analyzed. Depending on the strength of the electric field and the ratio of plasma to gyrofrequency, there are three different regimes in the evolution of the tail. The tail can be (1) stable with electrons accelerated to large parallel velocities, (2) unstable to Cerenkov resonance because of the depletion of the bulk and the formation of a positive slope, (3) unstable to the anomalous Doppler resonance instability driven by the large velocity anisotropy in the tail. Once an instability is triggered (Cerenkov or anomalous Doppler resonance) the tail relaxes into an isotropic distribution. The role of a convection type loss term is also discussed.

PTEN knockdown alters dendritic spine/protrusion morphology, not density

PubMed Central

Haws, Michael E.; Jaramillo, Thomas C.; Espinosa-Becerra, Felipe; Widman, Allie; Stuber, Garret D.; Sparta, Dennis R.; Tye, Kay M.; Russo, Scott J.; Parada, Luis F.; Kaplitt, Michael; Bonci, Antonello; Powell, Craig M.

2014-01-01

Mutations in phosphatase and tensin homolog deleted on chromosome ten (PTEN) are implicated in neuropsychiatric disorders including autism. Previous studies report that PTEN knockdown in neurons in vivo leads to increased spine density and synaptic activity. To better characterize synaptic changes in neurons lacking PTEN, we examined the effects of shRNA knockdown of PTEN in basolateral amygdala neurons on synaptic spine density and morphology using fluorescent dye confocal imaging. Contrary to previous studies in dentate gyrus, we find that knockdown of PTEN in basolateral amygdala leads to a significant decrease in total spine density in distal dendrites. Curiously, this decreased spine density is associated with increased miniature excitatory post-synaptic current frequency and amplitude, suggesting an increase in number and function of mature spines. These seemingly contradictory findings were reconciled by spine morphology analysis demonstrating increased mushroom spine density and size with correspondingly decreased thin protrusion density at more distal segments. The same analysis of PTEN conditional deletion in dentate gyrus demonstrated that loss of PTEN does not significantly alter total density of dendritic protrusions in the dentate gyrus, but does decrease thin protrusion density and increases density of more mature mushroom spines. These findings suggest that, contrary to previous reports, PTEN knockdown may not induce de novo spinogenesis, but instead may increase synaptic activity by inducing morphological and functional maturation of spines. Furthermore, behavioral analysis of basolateral amygdala PTEN knockdown suggests that these changes limited only to the basolateral amygdala complex may not be sufficient to induce increased anxiety-related behaviors. PMID:24264880

Dysphagia associated with cervical spine and postural disorders.

PubMed

Papadopoulou, Soultana; Exarchakos, Georgios; Beris, Alexander; Ploumis, Avraam

2013-12-01

Difficulties with swallowing may be both persistent and life threatening for the majority of those who experience it irrespective of age, gender, and race. The purpose of this review is to define oropharyngeal dysphagia and describe its relationship to cervical spine disorders and postural disturbances due to either congenital or acquired disorders. The etiology and diagnosis of dysphagia are analyzed, focusing on cervical spine pathology associated with dysphagia as severe cervical spine disorders and postural disturbances largely have been held accountable for deglutition disorders. Scoliosis, kyphosis–lordosis, and osteophytes are the primary focus of this review in an attempt to elucidate the link between cervical spine disorders and dysphagia. It is important for physicians to be knowledgeable about what triggers oropharyngeal dysphagia in cases of cervical spine and postural disorders. Moreover, the optimum treatment for dysphagia, including the use of therapeutic maneuvers during deglutition, neck exercises, and surgical treatment, is discussed.

Pediatric Cervical Spine Injuries: A Rare But Challenging Entity.

PubMed

Baumann, Florian; Ernstberger, Toni; Neumann, Carsten; Nerlich, Michael; Schroeder, Gregory D; Vaccaro, Alexander R; Loibl, Markus

2015-08-01

Injuries to the cervical spine in pediatric patients are uncommon. A missed injury can have devastating consequences in this age group. Because of the lack of routine in diagnosis and management of pediatric cervical spine injuries (PCSI), each of these cases represents a logistic and personal challenge. By means of clinical cases, we demonstrate key points in diagnostics and treatment of pediatric spine injuries. We highlight typical pediatric injury patterns and more adult-like injuries. The most common cause of injury is blunt trauma. There is an age-related pattern of injuries in pediatric patients. Children under the age of 8 frequently sustain ligamentous injuries in the upper cervical spine. After the age of 8, the biomechanics of the cervical spine are similar to adults, and therefore, bony injuries of the subaxial cervical spine are most likely to occur. Clinical presentation of PCSI is heterogeneous. Younger children can neither interpret nor communicate neurological abnormalities, which make timely and accurate diagnosis difficult. Plain radiographs are often misinterpreted. We find different types of injuries at different locations, because of different biomechanical properties of the immature spine. We outline that initial management is crucial for long-term outcome. Knowledge of biomechanical properties and radiographic presentation of the immature spine can improve the awareness for PCSI. Diagnosis and management of pediatric patients after neck trauma can be demanding. Level IV.

Biophysical model of the role of actin remodeling on dendritic spine morphology

PubMed Central

Miermans, C. A.; Kusters, R. P. T.; Hoogenraad, C. C.; Storm, C.

2017-01-01

Dendritic spines are small membranous structures that protrude from the neuronal dendrite. Each spine contains a synaptic contact site that may connect its parent dendrite to the axons of neighboring neurons. Dendritic spines are markedly distinct in shape and size, and certain types of stimulation prompt spines to evolve, in fairly predictable fashion, from thin nascent morphologies to the mushroom-like shapes associated with mature spines. It is well established that the remodeling of spines is strongly dependent upon the actin cytoskeleton inside the spine. A general framework that details the precise role of actin in directing the transitions between the various spine shapes is lacking. We address this issue, and present a quantitative, model-based scenario for spine plasticity validated using realistic and physiologically relevant parameters. Our model points to a crucial role for the actin cytoskeleton. In the early stages of spine formation, the interplay between the elastic properties of the spine membrane and the protrusive forces generated in the actin cytoskeleton propels the incipient spine. In the maturation stage, actin remodeling in the form of the combined dynamics of branched and bundled actin is required to form mature, mushroom-like spines. Importantly, our model shows that constricting the spine-neck aids in the stabilization of mature spines, thus pointing to a role in stabilization and maintenance for additional factors such as ring-like F-actin structures. Taken together, our model provides unique insights into the fundamental role of actin remodeling and polymerization forces during spine formation and maturation. PMID:28158194

Spine micromorphology of normal and hyperhydric Mammillaria gracilis Pfeiff. (Cactaceae) shoots.

PubMed

Peharec, P; Posilović, H; Balen, B; Krsnik-Rasol, M

2010-07-01

Artificial conditions of tissue culture affect growth and physiology of crassulacean acid metabolism plants which often results in formation of hyperhydric shoots. In in vitro conditions Mammillaria gracilis Pfeiff. (Cactaceae) growth switches from organized to unorganized way, producing a habituated organogenic callus which simultaneously regenerates morphologically normal as well as altered hyperhydric shoots. In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16-17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11-12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed numerous long trichomes, which were more elongated on spines of the hyperhydric shoots; the corresponding structures on spine surface of pot-grown plants were noticed only as small protrusions. Scanning electron microscopy morphometric studies showed that the spines of pot-grown plants were significantly longer compared to the spines of shoots grown in tissue culture. Moreover, transverse section shape varies from elliptical in pot-grown plants to circular in normal and hyperhydric shoots grown in vitro. Cluster and correspondence analyses performed on the scanning electron microscope obtained results suggest great variability among spines of pot-grown plants. Spines of in vitro grown normal and hyperhydric shoots showed low level of morphological variation among themselves despite the

Fractal and Chaos Analysis for Dynamics of Radon Exhalation from Uranium Mill Tailings

NASA Astrophysics Data System (ADS)

Li, Yongmei; Tan, Wanyu; Tan, Kaixuan; Liu, Zehua; Xie, Yanshi

2016-08-01

Tailings from mining and milling of uranium ores potentially are large volumes of low-level radioactive materials. A typical environmental problem associated with uranium tailings is radon exhalation, which can significantly pose risks to environment and human health. In order to reduce these risks, it is essential to study the dynamical nature and underlying mechanism of radon exhalation from uranium mill tailings. This motivates the conduction of this study, which is based on the fractal and chaotic methods (e.g. calculating the Hurst exponent, Lyapunov exponent and correlation dimension) and laboratory experiments of the radon exhalation rates. The experimental results show that the radon exhalation rate from uranium mill tailings is highly oscillated. In addition, the nonlinear analyses of the time series of radon exhalation rate demonstrate the following points: (1) the value of Hurst exponent much larger than 0.5 indicates non-random behavior of the radon time series; (2) the positive Lyapunov exponent and non-integer correlation dimension of the time series imply that the radon exhalation from uranium tailings is a chaotic dynamical process; (3) the required minimum number of variables should be five to describe the time evolution of radon exhalation. Therefore, it can be concluded that the internal factors, including heterogeneous distribution of radium, and randomness of radium decay, as well as the fractal characteristics of the tailings, can result in the chaotic evolution of radon exhalation from the tailings.

Cervical Spine MRI in Abused Infants.

ERIC Educational Resources Information Center

Feldman, Kenneth W.; And Others

1997-01-01

This study attempted to use cervical spine magnetic resonance imaging (MRI) to detect cord injury in 12 dead children with head injury from child abuse. Eighty percent of children autopsied had small cervical spine hemorrhages; MRI did not identify them and did not identify cord injury in any child studied, indicating that MRI scans are probably…

Finding line of action of the force exerted on erect spine based on lateral bending test in personalization of scoliotic spine models.

PubMed

Jalalian, Athena; Tay, Francis Eng Hock; Arastehfar, Soheil; Gibson, Ian; Liu, Gabriel

2017-04-01

In multi-body models of scoliotic spine, personalization of mechanical properties of joints significantly improves reconstruction of the spine shape. In personalization methods based on lateral bending test, simulation of bending positions is an essential step. To simulate, a force is exerted on the spine model in the erect position. The line of action of the force affects the moment of the force about the joints and thus, if not correctly identified, causes over/underestimation of mechanical properties. Therefore, we aimed to identify the line of action, which has got little attention in previous studies. An in-depth analysis was performed on the scoliotic spine movement from the erect to four spine positions in the frontal plane by using pre-operative X-rays of 18 adolescent idiopathic scoliosis (AIS) patients. To study the movement, the spine curvature was considered as a 2D chain of micro-scale motion segments (MMSs) comprising rigid links and 1-degree-of-freedom (DOF) rotary joints. It was found that two MMSs representing the inflection points of the erect spine had almost no rotation (0.0028° ± 0.0021°) in the movement. The small rotation can be justified by weak moment of the force about these MMSs due to very small moment arm. Therefore, in the frontal plane, the line of action of the force to simulate the left/right bending position was defined as the line that passes through these MMSs in the left/right bending position. Through personalization of a 3D spine model for our patients, we demonstrated that our line of action could result in good estimates of the spine shape in the bending positions and other positions not included in the personalization, supporting our proposed line of action.

Human mesenchymal stem cells and biomaterials interaction: a promising synergy to improve spine fusion.

PubMed

Barbanti Brodano, G; Mazzoni, E; Tognon, M; Griffoni, C; Manfrini, M

2012-05-01

Spine fusion is the gold standard treatment in degenerative and traumatic spine diseases. The bone regenerative medicine needs (i) in vitro functionally active osteoblasts, and/or (ii) the in vivo induction of the tissue. The bone tissue engineering seems to be a very promising approach for the effectiveness of orthopedic surgical procedures, clinical applications are often hampered by the limited availability of bone allograft or substitutes. New biomaterials have been recently developed for the orthopedic applications. The main characteristics of these scaffolds are the ability to induce the bone tissue formation by generating an appropriate environment for (i) the cell growth and (ii) recruiting precursor bone cells for the proliferation and differentiation. A new prototype of biomaterials known as "bioceramics" may own these features. Bioceramics are bone substitutes mainly composed of calcium and phosphate complex salt derivatives. In this study, the characteristics bioceramics bone substitutes have been tested with human mesenchymal stem cells obtained from the bone marrow of adult orthopedic patients. These cellular models can be employed to characterize in vitro the behavior of different biomaterials, which are used as bone void fillers or three-dimensional scaffolds. Human mesenchymal stem cells in combination with biomaterials seem to be good alternative to the autologous or allogenic bone fusion in spine surgery. The cellular model used in our study is a useful tool for investigating cytocompatibility and biological features of HA-derived scaffolds.

Helmet Fit and Cervical Spine Motion in Collegiate Men's Lacrosse Athletes Secured to a Spine Board

PubMed Central

Petschauer, Meredith A.; Schmitz, Randy; Gill, Diane L.

2010-01-01

Abstract Context: Proper management of cervical spine injuries in men's lacrosse players depends in part upon the ability of the helmet to immobilize the head. Objective: To determine if properly and improperly fitted lacrosse helmets provide adequate stabilization of the head in the spine-boarded athlete. Design: Crossover study. Setting: Sports medicine research laboratory. Patients or Other Participants: Eighteen healthy collegiate men's lacrosse players. Intervention(s): Participants were asked to move their heads through 3 planes of motion after being secured to a spine board under 3 helmet conditions. Main Outcome Measure(s): Change in range of motion in the cervical spine was calculated for the sagittal, frontal, and transverse planes for both head-to-thorax and helmet-to-thorax range of motion in all 3 helmet conditions (properly fitted, improperly fitted, and no helmet). Results: Head-to-thorax range of motion with the properly fitted and improperly fitted helmets was greater than in the no-helmet condition (P < .0001). In the sagittal plane, range of motion was greater with the improperly fitted helmet than with the properly fitted helmet. No difference was observed in helmet-to-thorax range of motion between properly and improperly fitted helmet conditions. Head-to-thorax range of motion was greater than helmet-to-thorax range of motion in all 3 planes (P < .0001). Conclusions: Cervical spine motion was minimized the most in the no-helmet condition, indicating that in lacrosse players, unlike football players, the helmet may need to be removed before stabilization. PMID:20446833

Wind-Tunnel Tests of the 1/9-Scale Model of the Curtiss XP-62 Airplane with Various Vertical Tail Arrangements

NASA Technical Reports Server (NTRS)

Wallace, Arthur R.; Recant, I.G.

1943-01-01

The effect of various vertical tail arrangements upon the stability and control characteristics of an XP-62 fighter model was investigated. Rudder-free yaw characteristics with take-off power and flaps deflected were satisfactory after dorsal fin modifications. Directional stability was obtained with all modified vertical tails. Satisfactory rudder effectiveness resulted partly because the dual-rotation propellers produced no asymmetric yawing moments. Pedal forces in sideslips were undesirably large but may be easily reduced.

Evaluation and management of 2 ferocactus spines in the orbit.

PubMed

Russell, David J; Kim, Tim I; Kubis, Kenneth

2013-01-01

A 49-year-old woman, who had fallen face first in a cactus 1 week earlier, presented with a small, mobile, noninflamed subcutaneous nodule at the rim of her right lateral orbit with no other functional deficits. A CT scan was obtained, which revealed a 4-cm intraorbital tubular-shaped foreign body resembling a large cactus spine. A second preoperative CT scan, obtained for an intraoperative guidance system, demonstrated a second cactus spine, which was initially not seen on the first CT scan. Both spines were removed surgically without complication. The authors discuss factors that can cause diagnosis delay, review the radiographic features of cactus spines, and discuss the often times benign clinical course of retained cactus spine foreign bodies. To the authors' knowledge, this is the first case report of cactus spines in the orbit. Health-care professionals should have a low threshold for imaging in cases of traumatic injuries involving cactus spines.

Vertebral artery injuries in cervical spine surgery.

PubMed

Lunardini, David J; Eskander, Mark S; Even, Jesse L; Dunlap, James T; Chen, Antonia F; Lee, Joon Y; Ward, Timothy W; Kang, James D; Donaldson, William F

2014-08-01

Vertebral artery injuries (VAIs) are rare but serious complications of cervical spine surgery, with the potential to cause catastrophic bleeding, permanent neurologic impairment, and even death. The present literature regarding incidence of this complication largely comprises a single surgeon or small multicenter case series. We sought to gather a large sample of high-volume surgeons to adequately characterize the incidence and risk factors for VAI, management strategies used, and patient outcomes after VAI. The study was constructed as a cross-sectional study comprising all cervical spine patients operated on by the members of the international Cervical Spine Research Society (CSRS). All patients who have undergone cervical spine surgery by a current member of CSRS as of the spring of 2012. For each surgeon surveyed, we collected self-reported measures to include the number of cervical cases performed in the surgeon's career, the number of VAIs encountered, the stage of the case during which the injury occurred, the management strategies used, and the overall patient outcome after injury. An anonymous 10-question web-based survey was distributed to the members of the CSRS. Statistical analysis was performed using Student t tests for numerical outcomes and chi-squared analysis for categorical variables. One hundred forty-one CSRS members (of 195 total, 72%) responded to the survey, accounting for a total of 163,324 cervical spine surgeries performed. The overall incidence of VAI was 0.07% (111/163,324). Posterior instrumentation of the upper cervical spine (32.4%), anterior corpectomy (23.4%), and posterior exposure of the cervical spine (11.7%) were the most common stages of the case to result in an injury to the vertebral artery. Discectomy (9%) and anterior exposure of the spine (7.2%) were also common time points for an arterial injury. One-fifth (22/111) of all VAI involved an anomalous course of the vertebral artery. The most common management of VAI was by

Subsequent, unplanned spine surgery and life survival of patients operated for neuropathic spine deformity.

PubMed

Asher, Marc A; Lai, Sue-Min; Burton, Douglas C

2012-01-01

Retrospective study of a prospectively assembled cohort. To characterize the survival from subsequent spine surgery and the life survival of patients treated surgically for severe spinal deformity due to neuropathic diseases. Survivorship analysis is widely used to study the natural history of disease processes and of treatments provided, but has very seldom been used to study patients' course after surgery for spinal deformity associated with neuropathic diseases. Patients with neuropathic spinal deformity treated with primary posterior instrumentation and arthrodesis from 1989 through 2002 were identified and studied by review of charts and radiographs, and by mail survey. Subsequent spine surgery and death events, and the time interval from surgery were identified. Fifteen variables possibly influencing survivorship were studied. There were no perioperative deaths, spinal cord injuries, or acute wound infections in the 117 eligible patients. Reoperation and life survival statuses were available for 110 patients (94%) at an average follow-up of 11.89 years (±5.3; range: 2-20.9 yr). Twelve patients (11%) had subsequent spine surgery. Survival from subsequent spine surgery was 91% at 5 years, 90% at 10 and 15 years, and 72% at 20 years. Proximal fixation problems occurred in 4 patients. Twenty-two patients (20%) had died from 4 to 20 years postoperative. Life survival was 98% at 5 years, 89% at 10 years, 81% at 15 years, and 56% at 20 years. The only variable associated with life survival was the occurrence of one or more perioperative complications, P = 0.0032. The younger half of the series at operation (<13.75 yr) was significantly more likely to have one or more perioperative complications, P = 0.0068. Spinal deformity type and magnitude were similar for the younger and older halves of the patients. Life survival of the patients with cerebral-palsy and not-cerebral-palsy upper motor neuron disease was not different. One-hundred-two of 105 were at least

Acclimation capacity of the three-spined stickleback (Gasterosteus aculeatus, L.) to a sudden biological stress following a polymetallic exposure.

PubMed

Le Guernic, Antoine; Sanchez, Wilfried; Palluel, Olivier; Bado-Nilles, Anne; Floriani, Magali; Turies, Cyril; Chadili, Edith; Vedova, Claire Della; Cavalié, Isabelle; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-10-01

To get closer to the environmental reality, ecotoxicological studies should no longer consider the evaluation of a single pollutant, but rather combination of stress and their interaction. The aim of this study was to determine if responses of a fish to a sudden biological stress could be modified by a prior exposure to a chemical stress (a polymetallic contamination). For this purpose, in situ experiment was conducted in three ponds in the Haute-Vienne department (France). One pond was chosen for its high uranium concentration due to uranium mine tailings, and the two other ponds, which were not submitted to these tailings. Three-spined sticklebacks (Gasterosteus aculeatus) were caged in these ponds for 14 days. After this period, fish were submitted to a biological stress, exerted by lipopolysaccharides injection after anesthesia, and were sacrificed 4 days after these injections for multi-biomarkers analyses (leucocyte viability, phagocytic capacity and reactive oxygen species production, antioxidant peptide and enzymes, lipid peroxidation and DNA damage). The pond which received uranium mine tailings had higher metallic concentrations. Without biological stress, sticklebacks caged in this pond presented an oxidative stress, with increasing of reactive oxygen species levels, modification of some parts of the antioxidant system, and lipid peroxidation. Caging in the two most metal-contaminated ponds resulted in an increase of susceptibility of sticklebacks to the biological stress, preventing their phagocytic responses to lipopolysaccharides and modifying their glutathione contents and glutathione-S-transferase activity.

Determination of the reaction rate coefficient of sulphide mine tailings deposited under water.

PubMed

Awoh, Akué Sylvette; Mbonimpa, Mamert; Bussière, Bruno

2013-10-15

The efficiency of a water cover to limit dissolved oxygen (DO) availability to underlying acid-generating mine tailings can be assessed by calculating the DO flux at the tailings-water interface. Fick's equations, which are generally used to calculate this flux, require knowing the effective DO diffusion coefficient (Dw) and the reaction (consumption) rate coefficient (Kr) of the tailings, or the DO concentration profile. Whereas Dw can be accurately estimated, few studies have measured the parameter Kr for submerged sulphide tailings. The objective of this study was to determine Kr for underwater sulphide tailings in a laboratory experiment. Samples of sulphide mine tailings (an approximately 6 cm layer) were placed in a cell under a water cover (approximately 2 cm) maintained at constant DO concentration. Two tailings were studied: TA1 with high sulphide content (83% pyrite) and TA2 with low sulphide content (2.8% pyrite). DO concentration was measured with a microelectrode at various depths above and below the tailings-water interface at 1 mm intervals. Results indicate that steady-state condition was rapidly attained. As expected, a diffusive boundary layer (DBL) was observed in all cases. An iterative back-calculation process using the numerical code POLLUTEv6 and taking the DBL into account provided the Kr values used to match calculated and experimental concentration profiles. Kr obtained for tailings TA1 and TA2 was about 80 d(-1) and 6.5 d(-1), respectively. For comparison purposes, Kr obtained from cell tests on tailings TA1 was lower than Kr calculated from the sulphate production rate obtained from shake-flask tests. Steady-state DO flux at the water-tailings interface was then calculated with POLLUTEv6 using tailings characteristics Dw and Kr. For the tested conditions, DO flux ranged from 608 to 758 mg O2/m(2)/d for tailings TA1 and from 177 to 221 mg O2/m(2)/d for tailings TA2. The impact of placing a protective layer of inert material over

Phytoremediation of Alberta oil sand tailings using native plants and fungal endophytes

NASA Astrophysics Data System (ADS)

Repas, T.; Germida, J.; Kaminskyj, S.

2012-04-01

Fungal endophytes colonize host plants without causing disease. Some endophytes confer plant tolerance to harsh environments. One such endophyte, Trichoderma harzianum strain TSTh20-1, was isolated from a plant growing on Athabasca oil sand tailings. Tailing sands are a high volume waste product from oil sand extraction that the industry is required to remediate. Tailing sands are low in organic carbon and mineral nutrients, and are hydrophobic due to residual polyaromatic hydrocarbons. Typically, tailing sands are remediated by planting young trees in large quantities of mulch plus mineral fertilizer, which is costly and labour intensive. In greenhouse trials, TSTh20-1 supports growth of tomato seedlings on tailing sands without fertilizer. The potential use of TSTh20-1 in combination with native grasses and forbs to remediate under field conditions is being assessed. Twenty-three commercially available plant species are being screened for seed germination and growth on tailing sands in the presence of TSTh20-1. The best candidates from this group will be used in greenhouse and small scale field trials. Potential mechanisms that contribute to endophyte-induced plant growth promotion, such as plant hormone production, stress tolerance, mineral solubilization, and uptake are also being assessed. As well, TSTh20-1 appears to be remarkably frugal in its nutrient requirements and the possibility that this attribute is characteristic of other plant-fungal endophytes from harsh environments is under study.

Philosophy and concepts of modern spine surgery.

PubMed

José-Antonio, Soriano-Sánchez; Baabor-Aqueveque, Marcos; Silva-Morales, Francisco

2011-01-01

The main goal of improving pain and neurological deficit in the practice of spine surgery is changing for a more ambitious goal, namely to improve the overall quality of life and the future of patients through three major actions (1) preserving the vertebral anatomical structures; (2) preserving the paravertebral anatomical structures; and (3) preserving the functionality of the segment. Thus, three new concepts have emerged (a) minimal surgery; (b) minimal access surgery; and (c) motion preservation surgery. These concepts are covered in a new term, minimally invasive spine surgery (MISS) The term "MISS" is not about one or several particular surgical techniques, but a new way of thinking, a new philosophy. Although the development of minimally invasive spine surgery is recent, its application includes all spine segments and almost all the existing conditions, including deformities.Evidence-based medicine (EBM), a term coined by Alvan Feinstein in the 1960s (Feinstein A (1964) Annals of Internal Medicine 61: 564-579; Feinstein A (1964) Annals of Internal Medicine 61: 757-781; Feinstein A (1964) Annals of Internal Medicine 61: 944-965; Feinstein A (1964) Annals of Internal Medicine 61: 1162-1193.), emphasizes the possibility of combining art and science following the strict application of scientific methods in the treatment of patients (Feinstein A (1964) Annals of Internal Medicine 61: 944-965; Feinstein A (1964) Annals of Internal Medicine 61: 1162-1193.), which may represent the advantages of objectivity and rationality in the use of different treatments (Fig. 11). However, EBM has many obvious defects, especially in spine surgery it is almost impossible to develop double-blind protocols (Andersson G, Bridwell K, Danielsson A, et al (2007) Spine 32: S64-S65.). In most cases, the only evidence one can find in the literature is the lack of evidence (Resnick D (2007) Spine 32:S15-S19.), however, the lack of evidence does not mean its absence. Only then, with a

Principles of management of osteometabolic disorders affecting the aging spine.

PubMed

Hadjipavlou, Alexander G; Katonis, Paul G; Tzermiadianos, Michael N; Tsoukas, George M; Sapkas, George

2003-10-01

Osteoporosis is the most common contributing factor of spinal fractures, which characteristically are not generally known to produce spinal cord compression symptoms. Recently, an increasing number of medical reports have implicated osteoporotic fractures as a cause of serious neurological deficit and painful disabling spinal deformities. This has been corroborated by the present authors as well. These complications are only amenable to surgical management, requiring instrumentation. Instrumenting an osteoporotic spine, although a challenging task, can be accomplished if certain guidelines for surgical techniques are respected. Neurological deficits respond equally well to an anterior or posterior decompression, provided this is coupled with multisegmental fixation of the construct. With the steady increase in the elderly population, it is anticipated that the spine surgeon will face serious complications of osteoporotic spines more frequently. With regard to surgery, however, excellent correction of deformities can be achieved, by combining anterior and posterior approaches. Paget's disease of bone (PD) is a non-hormonal osteometabolic disorder and the spine is the second most commonly affected site. About one-third of patients with spinal involvement exhibit symptoms of clinical stenosis. In only 12-24% of patients with PD of the spine is back pain attributed solely to PD, while in the majority of patients, back pain is either arthritic in nature or a combination of a pagetic process and coexisting arthritis. In this context, one must be certain before attributing low back pain to PD exclusively, and antipagetic medical treatment alone may be ineffective. Neural element dysfunction may be attributed to compressive myelopathy by pagetic bone overgrowth, pagetic intraspinal soft tissue overgrowth, ossification of epidural fat, platybasia, spontaneous bleeding, sarcomatous degeneration and vertebral fracture or subluxation. Neural dysfunction can also result from

Setting the equation: establishing value in spine care.

PubMed

Resnick, Daniel K; Tosteson, Anna N A; Groman, Rachel F; Ghogawala, Zoher

2014-10-15

Topic review. Describe value measurement in spine care and discuss the motivation for, methods for, and limitations of such measurement. Spinal disorders are common and are an important cause of pain and disability. Numerous complementary and competing treatment strategies are used to treat spinal disorders, and the costs of these treatments is substantial and continue to rise despite clear evidence of improved health status as a result of these expenditures. The authors present the economic and legislative imperatives forcing the assessment of value in spine care. The definition of value in health care and methods to measure value specifically in spine care are presented. Limitations to the utility of value judgments and caveats to their use are presented. Examples of value calculations in spine care are presented and critiqued. Methods to improve and broaden the measurement of value across spine care are suggested, and the role of prospective registries in measuring value is discussed. Value can be measured in spine care through the use of appropriate economic measures and patient-reported outcomes measures. Value must be interpreted in light of the perspective of the assessor, the duration of the assessment period, the degree of appropriate risk stratification, and the relative value of treatment alternatives.

Do Biological and Bedsite Characteristics Influence Survival of Neonatal White-Tailed Deer?

DOE PAGES

Chitwood, Michael Colter; Lashley, Marcus A.; Kilgo, John C.; ...

2015-03-03

Coyotes recently expanded into the eastern U.S. and potentially have caused localized white-tailed deer population declines. Research has focused on quantifying coyote predation on neonates, but little research has addressed the potential influence of bedsite characteristics on survival. In 2011 and 2012, we radiocollared 65 neonates, monitored them intensively for 16 weeks, and assigned mortality causes.We used Program MARK to estimate survival to 16 weeks and included biological covariates (i.e., sex, sibling status [whether or not it had a sibling], birth weight, and Julian date of birth). Survival to 16 weeks was 0.141 (95% CI = 0.075-0.249) and the topmore » model included only sibling status, which indicated survival was lower for neonates that had a sibling. Predation was the leading cause of mortality (35 of 55; 64%) and coyotes were responsible for the majority of depredations (30 of 35; 86%). Additionally, we relocated neonates for the first 10 days of life and measured distance to firebreak, visual obstruction, and plant diversity at bedsites. Survival of predation to 10 days (0.726; 95% CI = 0.586-0.833) was weakly associated with plant diversity at bedsites but not related to visual obstruction. Our results indicate that neonate survival was low and coyote predation was an important source of mortality, which corroborates several recent studies from the region. Additionally, we detected only weak support for bedsite cover as a covariate to neonate survival, which indicates that mitigating effects of coyote predation on neonates may be more complicated than simply managing for increased hiding cover.« less

Diffuse idiopathic skeletal hyperostosis association with thoracic spine kyphosis: a cross-sectional study for the Health Aging and Body Composition Study.

PubMed

Nardo, Lorenzo; Lane, Nancy E; Parimi, Neeta; Cawthon, Peggy M; Fan, Bo; Shepherd, John; Cauley, Jane; Zucker-Levin, Audrey; Murphy, Rachel A; Katzman, Wendy B

2014-11-15

A descriptive study of the association between diffuse idiopathic skeletal hyperostosis (DISH) and kyphosis. To investigate the association of DISH with Cobb angle of kyphosis in a large cohort of older subjects from the Health Aging and Body Composition Study. DISH and thoracic kyphosis are well-defined radiographical findings in spines of older individuals. Characteristics of DISH (ossifications between vertebral segments) reflect changes of spine anatomy and physiology that may be associated with Cobb angle of kyphosis. Using data from 1172 subjects aged 70 to 79 years, we measured DISH and Cobb angle of kyphosis from computed tomographic lateral scout scans. Characteristics of participants with and without DISH were assessed using the χ² and t tests. Association between DISH and Cobb angle was analyzed using linear regression. Cobb angle and DISH relationship was assessed at different spine levels (thoracic and lumbar). DISH was identified on computed tomographic scout scan in 152 subjects with 101 cases in only the thoracic spine and 51 in both thoracic and lumbar spine segments. The mean Cobb angle of kyphosis in the analytic sample was 31.3° (standard deviation = 11.2). The presence of DISH was associated with a greater Cobb angle of 9.1° and 95% confidence interval (95% CI) (5.6-12.6) among African Americans and a Cobb angle of 2.9° and 95% CI (0.5-5.2) among Caucasians compared with those with no DISH. DISH in the thoracic spine alone was associated with a greater Cobb angle of 10.6° and 95% CI (6.5-14.7) in African Americans and a Cobb angle of 3.8° and 95% CI (1.0-6.5) in Caucasians compared with those with no DISH. DISH is associated with greater Cobb angle of kyphosis, especially when present in the thoracic spine alone. The association of DISH with Cobb angle is stronger within the African American population.

Sagittal Thoracic and Lumbar Spine Profiles in Upright Standing and Lying Prone Positions Among Healthy Subjects: Influence of Various Biometric Features.

PubMed

Salem, Walid; Coomans, Ysaline; Brismée, Jean-Michel; Klein, Paul; Sobczak, Stéphane; Dugailly, Pierre-Michel

2015-08-01

A prospective study was performed on the assessment of both thoracic and lumbar spine sagittal profiles (from C7 to S1). To propose a new noninvasive method for measuring the spine curvatures in standing and lying prone positions and to analyze their relationship with various biometric characteristics. Modifications of spine curvatures (i.e. lordosis or kyphosis) are of importance in the development of spinal disorders. Studies have emphasized the development of new devices to measure the spine sagittal profiles using a noninvasive and low-cost method. To date, it has not been applied for analyzing both lumbar and thoracic alterations for various positioning. Seventy-five healthy subjects (mean 22.6 ± 4.3 yr) were recruited to participate in this study. Thoracic and lumbar sagittal profiles were assessed in standing and lying prone positions using a 3D digitizer. In addition, several biometric data were collected including maximal trunk isometric strength for flexion and extension movement. Statistical analysis consisted in data comparisons of spine profiles and a multivariate analysis including biometric features, to classify individuals considering low within- and high between-variability. Kyphosis and lordosis angles decreased significantly from standing to lying prone position by an average of 13.4° and 16.6°, respectively. Multivariate analysis showed a sample clustering of 3 homogenous subgroups. The first group displayed larger lordosis and flexibility, and had low data values for height, weight, and strength. The second group had lower values than the overall trend of the whole sample, whereas the third group had larger score values for the torques, height, weight, waist, body mass index, and kyphosis angle but a reduced flexibility. The present results demonstrate a significant effect of the positioning on both thoracic and lumbar spine sagittal profiles and highlight the use of cluster analysis to categorize subgroups after biometric characteristics

The new idea of transporting tailings-logs in tailings slurry pipeline and the innovation of technology of mining waste-fill method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Yu; Wang Fuji; Tao Yan

2000-07-01

This paper introduced a new idea of transporting mine tailings-logs in mine tailings-slurry pipeline and a new technology of mine cemented filing of tailings-logs with tailings-slurry. The hydraulic principles, the compaction of tailings-logs and the mechanic function of fillbody of tailings-logs cemented by tailings-slurry have been discussed.

Airway management in cervical spine injury

PubMed Central

Austin, Naola; Krishnamoorthy, Vijay; Dagal, Arman

2014-01-01

To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury. PMID:24741498

Dual energy X-ray absorptiometry spine scans to determine abdominal fat in post-menopausal women

PubMed Central

Bea, J. W.; Blew, R. M.; Going, S. B.; Hsu, C-H; Lee, M. C.; Lee, V. R.; Caan, B.J.; Kwan, M.L.; Lohman, T. G.

2016-01-01

Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. Objectives We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. Methods Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n=103). ROIs were 1) lumbar vertebrae L2-L4 and 2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and 3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N=25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. Results Mean age, BMI and total body fat were: 66.1 ± 4.8y, 25.8 ± 3.8kg/m2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R2: 0.83) and L2-IC (Adj.R2:0.84) abdominal fat (%) well; the adjusted R2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R2: 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat respectively). Conclusions The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in post-menopausal chronic disease risk prediction models. PMID:27416964

Secondary neurulation: Fate-mapping and gene manipulation of the neural tube in tail bud.

PubMed

Shimokita, Eisuke; Takahashi, Yoshiko

2011-04-01

The body tail is a characteristic trait of vertebrates, which endows the animals with a variety of locomotive functions. During embryogenesis, the tail develops from the tail bud, where neural and mesodermal tissues make a major contribution. The neural tube in the tail bud develops by the process known as secondary neurulation (SN), where mesenchymal cells undergo epithelialization and tubulogenesis. These processes contrast with the well known primary neurulation, which is achieved by invagination of an epithelial cell sheet. In this study we have identified the origin of SN-undergoing cells, which is located caudo-medially to Hensen's node of early chicken embryo. This region is distinctly fate-mapped from tail-forming mesoderm. The identification of the presumptive SN region has allowed us to target this region with exogenous genes using in ovo electroporation techniques. The SN-transgenesis has further enabled an exploration of molecular mechanisms underlying mesenchymal-to-epithelial transition during SN, where activity levels of Cdc42 and Rac1 are critical. This is the first demonstration of molecular and cellular analyses of SN, which can be performed at a high resolution separately from tail-forming mesoderm. © 2011 The Authors. Journal compilation © 2011 Japanese Society of Developmental Biologists.

Short-term combined effects of thoracic spine thrust manipulation and cervical spine nonthrust manipulation in individuals with mechanical neck pain: a randomized clinical trial.

PubMed

Masaracchio, Michael; Cleland, Joshua A; Hellman, Madeleine; Hagins, Marshall

2013-03-01

Randomized clinical trial. To investigate the short-term effects of thoracic spine thrust manipulation combined with cervical spine nonthrust manipulation (experimental group) versus cervical spine nonthrust manipulation alone (comparison group) in individuals with mechanical neck pain. Research has demonstrated improved outcomes with both nonthrust manipulation directed at the cervical spine and thrust manipulation directed at the thoracic spine in patients with neck pain. Previous studies have not determined if thoracic spine thrust manipulation may increase benefits beyond those provided by cervical nonthrust manipulation alone. Sixty-four participants with mechanical neck pain were randomized into 1 of 2 groups, an experimental or comparison group. Both groups received 2 treatment sessions of cervical spine nonthrust manipulation and a home exercise program consisting of active range-of-motion exercises, and the experimental group received additional thoracic spine thrust manipulations. Outcome measures were collected at baseline and at a 1-week follow-up, and included the numeric pain rating scale, the Neck Disability Index, and the global rating of change. Participants in the experimental group demonstrated significantly greater improvements (P<.001) on both the numeric pain rating scale and Neck Disability Index at the 1-week follow-up compared to those in the comparison group. In addition, 31 of 33 (94%) participants in the experimental group, compared to 11 of 31 participants (35%) in the comparison group, indicated a global rating of change score of +4 or higher at the 1-week follow-up, with an associated number needed to treat of 2. Individuals with neck pain who received a combination of thoracic spine thrust manipulation and cervical spine nonthrust manipulation plus exercise demonstrated better overall short-term outcomes on the numeric pain rating scale, the Neck Disability Index, and the global rating of change.

The top 100 classic papers in lumbar spine surgery.

PubMed

Steinberger, Jeremy; Skovrlj, Branko; Caridi, John M; Cho, Samuel K

2015-05-15

Bibliometric review of the literature. To analyze and quantify the most frequently cited papers in lumbar spine surgery and to measure their impact on the entire lumbar spine literature. Lumbar spine surgery is a dynamic and complex field. Basic science and clinical research remain paramount in understanding and advancing the field. While new literature is published at increasing rates, few studies make long-lasting impacts. The Thomson Reuters Web of Knowledge was searched for citations of all papers relevant to lumbar spine surgery. The number of citations, authorship, year of publication, journal of publication, country of publication, and institution were recorded for each paper. The most cited paper was found to be the classic paper from 1990 by Boden et al that described magnetic resonance imaging findings in individuals without back pain, sciatica, and neurogenic claudication showing that spinal stenosis and herniated discs can be incidentally found when scanning patients. The second most cited study similarly showed that asymptomatic patients who underwent lumbar spine magnetic resonance imaging frequently had lumbar pathology. The third most cited paper was the 2000 publication of Fairbank and Pynsent reviewing the Oswestry Disability Index, the outcome-measure questionnaire most commonly used to evaluate low back pain. The majority of the papers originate in the United States (n=58), and most were published in Spine (n=63). Most papers were published in the 1990s (n=49), and the 3 most common topics were low back pain, biomechanics, and disc degeneration. This report identifies the top 100 papers in lumbar spine surgery and acknowledges those individuals who have contributed the most to the advancement of the study of the lumbar spine and the body of knowledge used to guide evidence-based clinical decision making in lumbar spine surgery today. 3.

Contrasting natural histories of thoracic spine pneumatocysts: resolution versus rapid enlargement

PubMed Central

Wilkinson, V H; Carroll, T; Hoggard, N

2011-01-01

An intraosseous pneumatocyst is an unusual cause of gas in a vertebral body and is rarely reported in the thoracic spine. We report the evolution of thoracic spine pneumatocysts, one that enlarged rapidly with resorption of fluid and one that resolved. A 65-year-old female with lower back and left leg pain underwent MRI of the lumbar spine, which demonstrated a well-defined lesion in a T10 vertebral body of low-signal on T1 and T2 weighted imaging. CT confirmed this as a gas-containing cyst. Review of previous imaging showed that this lesion had initially contained fluid and had expanded rapidly over 14 months. It also showed smaller pneumatocysts, which had resolved. The variable natural history and imaging features of pneumatocysts make them an important differential diagnosis of an intravertebral lesion. Their aetiology is not known, but previous case reports suggest that they can occur spontaneously or in association with vacuum phenomenon in adjacent discs or facet joints. Previous reports have observed that they can fill with granulation tissue or fluid, and the case we report demonstrates that this fluid can be resorbed and that the pneumatocyst can undergo rapid enlargement. A pneumatocyst is a differential diagnosis for an expanding intravertebral lesion of indeterminate MRI characteristics. The diagnosis can be made with CT if the lesion is gas or gas and fluid filled. PMID:21415298

Virtual endoscopic imaging of the spine.

PubMed

Kotani, Toshiaki; Nagaya, Shigeyuki; Sonoda, Masaru; Akazawa, Tsutomu; Lumawig, Jose Miguel T; Nemoto, Tetsuharu; Koshi, Takana; Kamiya, Koshiro; Hirosawa, Naoya; Minami, Shohei

2012-05-20

Prospective trial of virtual endoscopy in spinal surgery. To investigate the utility of virtual endoscopy of the spine in conjunction with spinal surgery. Several studies have described clinical applications of virtual endoscopy to visualize the inside of the bronchi, paranasal sinus, stomach, small intestine, pancreatic duct, and bile duct, but, to date, no study has described the use of virtual endoscopy in the spine. Virtual endoscopy is a realistic 3-dimensional intraluminal simulation of tubular structures that is generated by postprocessing of computed tomographic data sets. Five patients with spinal disease were selected: 2 patients with degenerative disease, 2 patients with spinal deformity, and 1 patient with spinal injury. Virtual endoscopy software allows an observer to explore the spinal canal with a mouse, using multislice computed tomographic data. Our study found that virtual endoscopy of the spine has advantages compared with standard imaging methods because surgeons can noninvasively explore the spinal canal in all directions. Virtual endoscopy of the spine may be useful to surgeons for diagnosis, preoperative planning, and postoperative assessment by obviating the need to mentally construct a 3-dimensional picture of the spinal canal from 2-dimensional computed tomographic scans.

Predicting surgical site infection after spine surgery: a validated model using a prospective surgical registry.

PubMed

Lee, Michael J; Cizik, Amy M; Hamilton, Deven; Chapman, Jens R

2014-09-01

The impact of surgical site infection (SSI) is substantial. Although previous study has determined relative risk and odds ratio (OR) values to quantify risk factors, these values may be difficult to translate to the patient during counseling of surgical options. Ideally, a model that predicts absolute risk of SSI, rather than relative risk or OR values, would greatly enhance the discussion of safety of spine surgery. To date, there is no risk stratification model that specifically predicts the risk of medical complication. The purpose of this study was to create and validate a predictive model for the risk of SSI after spine surgery. This study performs a multivariate analysis of SSI after spine surgery using a large prospective surgical registry. Using the results of this analysis, this study will then create and validate a predictive model for SSI after spine surgery. The patient sample is from a high-quality surgical registry from our two institutions with prospectively collected, detailed demographic, comorbidity, and complication data. An SSI that required return to the operating room for surgical debridement. Using a prospectively collected surgical registry of more than 1,532 patients with extensive demographic, comorbidity, surgical, and complication details recorded for 2 years after the surgery, we identified several risk factors for SSI after multivariate analysis. Using the beta coefficients from those regression analyses, we created a model to predict the occurrence of SSI after spine surgery. We split our data into two subsets for internal and cross-validation of our model. We created a predictive model based on our beta coefficients from our multivariate analysis. The final predictive model for SSI had a receiver-operator curve characteristic of 0.72, considered to be a fair measure. The final model has been uploaded for use on SpineSage.com. We present a validated model for predicting SSI after spine surgery. The value in this model is that it gives

Changing views of Cajal's neuron: the case of the dendritic spine.

PubMed

Segal, Menahem

2002-01-01

Ever since dendritic spines were first described in detail by Santiago Ramón y Cajal, they were assumed to underlie the physical substrate of long term memory in the brain. Recent time-lapse imaging of dendritic spines in live tissue, using confocal microscopy, have revealed an amazingly plastic structure, which undergoes continuous changes in shape and size, not intuitively related to its assumed role in long term memory. Functionally, the spine is shown to be an independent cellular compartment, able to regulate calcium concentration independently of its parent dendrite. The shape of the spine is instrumental in regulating the link between the synapse and the parent dendrite such that longer spines have less impact on the dendrite than shorter ones. The spine can be formed, change its shape and disappear in response to afferent stimulation, in a dynamic fashion, indicating that spine morphology is an important vehicle for structuring synaptic interactions. While this role is crucial in the developing nervous system, large variations in spine densities in the adult brain indicate that tuning of synaptic impact may be a role of spines throughout the life of a neuron.

Local Muscle Fatigue and 3D Kinematics of the Cervical Spine in Healthy Subjects.

PubMed

Niederer, Daniel; Vogt, Lutz; Pippig, Torsten; Wall, Rudolf; Banzer, Winfried

2016-01-01

The authors aimed to further explore the effects of local muscle fatigue on cervical 3D kinematics and the interrelationship between these kinematic characteristics and local muscle endurance capacity in the unimpaired cervical spine. Twenty healthy subjects (38 ± 10 years; 5 women) performed 2 × 10 maximal cervical flexion-extension movements. Isometric muscle endurance tests (prone/supine lying) were applied between sets to induce local muscle fatigue quantified by Borg scale rates of perceived exertion (RPE) and slope in mean power frequency (MPF; surface electromyography; m. sternocleidomastoideus, m. splenius capitis). Cervical motion characteristics (maximal range of motion [ROM], coefficient of variation of the 10 repetitive movements, mean angular velocity, conjunct movements in transversal and frontal plane) were calculated from raw 3D ultrasonic movement data. Average isometric strength testing duration for flexion and extension correlated to the cervical ROM (r = .49/r = .48; p < .05). However, Student's t test demonstrated no significant alterations in any kinematic parameter following local muscle fatigue (p > .05). Although subjects' cervical muscle endurance capacity and motor output seems to be conjugated, no impact of local cervical muscle fatigue on motor function was shown. These findings underline the importance of complementary measures to address muscular performance and kinematic characteristics in outcome assessment and functional rehabilitation of the cervical spine.

Dendritic spine dysgenesis contributes to hyperreflexia after spinal cord injury

PubMed Central

Bandaru, Samira P.; Liu, Shujun; Waxman, Stephen G.

2014-01-01

Hyperreflexia and spasticity are chronic complications in spinal cord injury (SCI), with limited options for safe and effective treatment. A central mechanism in spasticity is hyperexcitability of the spinal stretch reflex, which presents symptomatically as a velocity-dependent increase in tonic stretch reflexes and exaggerated tendon jerks. In this study we tested the hypothesis that dendritic spine remodeling within motor reflex pathways in the spinal cord contributes to H-reflex dysfunction indicative of spasticity after contusion SCI. Six weeks after SCI in adult Sprague-Dawley rats, we observed changes in dendritic spine morphology on α-motor neurons below the level of injury, including increased density, altered spine shape, and redistribution along dendritic branches. These abnormal spine morphologies accompanied the loss of H-reflex rate-dependent depression (RDD) and increased ratio of H-reflex to M-wave responses (H/M ratio). Above the level of injury, spine density decreased compared with below-injury spine profiles and spine distributions were similar to those for uninjured controls. As expected, there was no H-reflex hyperexcitability above the level of injury in forelimb H-reflex testing. Treatment with NSC23766, a Rac1-specific inhibitor, decreased the presence of abnormal dendritic spine profiles below the level of injury, restored RDD of the H-reflex, and decreased H/M ratios in SCI animals. These findings provide evidence for a novel mechanistic relationship between abnormal dendritic spine remodeling in the spinal cord motor system and reflex dysfunction in SCI. PMID:25505110

Context-dependent effects of noise on echolocation pulse characteristics in free-tailed bats

PubMed Central

Smotherman, Michael S.

2010-01-01

Background noise evokes a similar suite of adaptations in the acoustic structure of communication calls across a diverse range of vertebrates. Echolocating bats may have evolved specialized vocal strategies for echolocating in noise, but also seem to exhibit generic vertebrate responses such as the ubiquitous Lombard response. We wondered how bats balance generic and echolocation-specific vocal responses to noise. To address this question, we first characterized the vocal responses of flying free-tailed bats (Tadarida brasiliensis) to broadband noises varying in amplitude. Secondly, we measured the bats’ responses to band-limited noises that varied in the extent of overlap with their echolocation pulse bandwidth. We hypothesized that the bats’ generic responses to noise would be graded proportionally with noise amplitude, total bandwidth and frequency content, and consequently that more selective responses to band-limited noise such as the jamming avoidance response could be explained by a linear decomposition of the response to broadband noise. Instead, the results showed that both the nature and the magnitude of the vocal responses varied with the acoustic structure of the outgoing pulse as well as non-linearly with noise parameters. We conclude that free-tailed bats utilize separate generic and specialized vocal responses to noise in a context-dependent fashion. PMID:19672604

Lynx1 Limits Dendritic Spine Turnover in the Adult Visual Cortex

PubMed Central

Sajo, Mari

2016-01-01

Dendritic spine turnover becomes limited in the adult cerebral cortex. Identification of specific aspects of spine dynamics that can be unmasked in adulthood and its regulatory molecular mechanisms could provide novel therapeutic targets for inducing plasticity at both the functional and structural levels for robust recovery from brain disorders and injuries in adults. Lynx1, an endogenous inhibitor of nicotinic acetylcholine receptors, was previously shown to increase its expression in adulthood and thus to limit functional ocular dominance plasticity in adult primary visual cortex (V1). However, the role of this “brake” on spine dynamics is not known. We examined the contribution of Lynx1 on dendritic spine turnover before and after monocular deprivation (MD) in adult V1 with chronic in vivo imaging using two-photon microscopy and determined the spine turnover rate of apical dendrites of layer 5 (L5) and L2/3 pyramidal neurons in adult V1 of Lynx1 knock-out (KO) mice. We found that the deletion of Lynx1 doubled the baseline spine turnover rate, suggesting that the spine dynamics in the adult cortex is actively limited by the presence of Lynx1. After MD, adult Lynx1-KO mice selectively exhibit higher rate of spine loss with no difference in gain rate in L5 neurons compared with control wild-type counterparts, revealing a key signature of spine dynamics associated with robust functional plasticity in adult V1. Overall, Lynx1 could be a promising therapeutic target to induce not only functional, but also structural plasticity at the level of spine dynamics in the adult brain. SIGNIFICANCE STATEMENT Dendritic spine turnover becomes limited in the adult cortex. In mouse visual cortex, a premier model of experience-dependent plasticity, we found that the deletion of Lynx1, a nicotinic “brake” for functional plasticity, doubled the baseline spine turnover in adulthood, suggesting that the spine dynamics in the adult cortex is actively limited by Lynx1. After

Analysis of dendritic spine morphology in cultured CNS neurons.

PubMed

Srivastava, Deepak P; Woolfrey, Kevin M; Penzes, Peter

2011-07-13

Dendritic spines are the sites of the majority of excitatory connections within the brain, and form the post-synaptic compartment of synapses. These structures are rich in actin and have been shown to be highly dynamic. In response to classical Hebbian plasticity as well as neuromodulatory signals, dendritic spines can change shape and number, which is thought to be critical for the refinement of neural circuits and the processing and storage of information within the brain. Within dendritic spines, a complex network of proteins link extracellular signals with the actin cyctoskeleton allowing for control of dendritic spine morphology and number. Neuropathological studies have demonstrated that a number of disease states, ranging from schizophrenia to autism spectrum disorders, display abnormal dendritic spine morphology or numbers. Moreover, recent genetic studies have identified mutations in numerous genes that encode synaptic proteins, leading to suggestions that these proteins may contribute to aberrant spine plasticity that, in part, underlie the pathophysiology of these disorders. In order to study the potential role of these proteins in controlling dendritic spine morphologies/number, the use of cultured cortical neurons offers several advantages. Firstly, this system allows for high-resolution imaging of dendritic spines in fixed cells as well as time-lapse imaging of live cells. Secondly, this in vitro system allows for easy manipulation of protein function by expression of mutant proteins, knockdown by shRNA constructs, or pharmacological treatments. These techniques allow researchers to begin to dissect the role of disease-associated proteins and to predict how mutations of these proteins may function in vivo.

Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Lumbar Spine KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Lumbar Spine What's in this article? What ...

Asymmetric deformation structure of lava spine in Unzen Volcano, Japan

NASA Astrophysics Data System (ADS)

Miwa, T.; Okumura, S.; Matsushima, T.; Shimizu, H.

2013-12-01

Lava spine is commonly generated by effusive eruption of crystal-rich, dacitic-andesitic magmas. Especially, deformation rock on surface of lava spine has been related with processes of magma ascent, outgassing, and generation of volcanic earthquake (e.g., Cashman et al. 2008). To reveal the relationships and generation process of the spine, it is needed to understand a spatial distribution of the deformation rock. Here we show the spatial distribution of the deformation rock of lava spine in the Unzen volcano, Japan, to discuss the generation process of the spine. The lava spine in Unzen volcano is elongated in the E-W direction, showing a crest like shape with 150 long, 40 m wide and 50 m high. The lava spine is divided into following four parts: 1) Massive dacite part: Dense dacite with 30 m of maximum thickness, showing slickenside on the southern face; 2) Sheared dacite part: Flow band developed dacite with 1.0 m of maximum thickness; 3) Tuffisite part: Network of red colored vein develops in dacite with 0.5 m of maximum thickness; 4) Breccia part: Dacitic breccia with 10 m of maximum thickness. The Breccia part dominates in the northern part of the spine, and flops over Massive dacite part accross the Sheared dacite and Tuffisite parts. The slickenside on southern face of massive dacite demonstrates contact of solids. The slickenside breaks both of phenocryst and groundmass, demonstrating that the slickenside is formed after significant crystallization at the shallow conduit or on the ground surface. The lineation of the slickenside shows E-W direction with almost horizontal rake angle, which is consistent with the movement of the spine to an east before emplacement. Development of sub-vertical striation due to extrusion was observed on northern face of the spine (Hayashi, 1994). Therefore, we suggest that the spine just at extrusion consisted of Massive dacite, Sheared dacite, Tuffisite, Breccia, and Striation parts in the northern half of the spine. Such a

Probing the Interplay between Dendritic Spine Morphology and Membrane-Bound Diffusion.

PubMed

Adrian, Max; Kusters, Remy; Storm, Cornelis; Hoogenraad, Casper C; Kapitein, Lukas C

2017-11-21

Dendritic spines are protrusions along neuronal dendrites that harbor the majority of excitatory postsynapses. Their distinct morphology, often featuring a bulbous head and small neck that connects to the dendritic shaft, has been shown to facilitate compartmentalization of electrical and cytoplasmic signaling stimuli elicited at the synapse. The extent to which spine morphology also forms a barrier for membrane-bound diffusion has remained unclear. Recent simulations suggested that especially the diameter of the spine neck plays a limiting role in this process. Here, we examine the connection between spine morphology and membrane-bound diffusion through a combination of photoconversion, live-cell superresolution experiments, and numerical simulations. Local photoconversion was used to obtain the timescale of diffusive equilibration in spines and followed by global sparse photoconversion to determine spine morphologies with nanoscopic resolution. These morphologies were subsequently used to assess the role of morphology on the diffusive equilibration. From the simulations, we could determine a robust relation between the equilibration timescale and a generalized shape factor calculated using both spine neck width and neck length, as well as spine head size. Experimentally, we found that diffusive equilibration was often slower, but rarely faster than predicted from the simulations, indicating that other biological confounders further reduce membrane-bound diffusion in these spines. This shape-dependent membrane-bound diffusion in mature spines may contribute to spine-specific compartmentalization of neurotransmitter receptors and signaling molecules and thereby support long-term plasticity of synaptic contacts. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Experimental aerodynamic characteristics for slender bodies with thin wings and tail at angles of attack from 0 deg to 58 deg and Mach numbers from 0.6 to 2.0

NASA Technical Reports Server (NTRS)

Jorgensen, L. H.; Nelson, E. R.

1976-01-01

An experimental investigation was conducted by wind tunnel to measure the static aerodynamic characteristics for bodies of circular and elliptic cross section with various thin flat plate wings and a thin tail consisting of horizontal and vertical parts. The wings had aspect ratios of 4 and taper ratios of about 0, 0.25, and 0.5. Two additional wings, which had taper ratios near 0.25 and aspect ratios of about 3 and 5, were also tested in combination with the bodies and tail. All wings had about the same planform area. The exposed area of the horizontal portion of the tail was about 33 to 36 percent of the exposed area of the wings. The exposed area of the vertical tail fin was about 22 to 24 percent of the exposed area of the wings. The elliptic body, with an a/b = 2 cross section, had the same length and axial distribution of cross sectional area as the circular body. The circular body had a cylindrical aftersection of fineness ratio 7, and it was tested with the wings and tail in combination with tangent ogive noses that had fineness ratios of 2.5, 3.0, 3.5, and 5.0. In addition, an ogive nose with a rounded tip and an ogive nose with two different nose strake arrangements were used. Nineteen configuration combinations were tested at Mach numbers of 0.6, 0.9, 1.5, and 2.0 at angles of attack from 0 to 58 deg. The Reynolds numbers, based on body base diameter, were about 4.3 X 100,000.

Delayed stabilization of dendritic spines in fragile X mice.

PubMed

Cruz-Martín, Alberto; Crespo, Michelle; Portera-Cailliau, Carlos

2010-06-09

Fragile X syndrome (FXS) causes mental impairment and autism through transcriptional silencing of the Fmr1 gene, resulting in the loss of the RNA-binding protein fragile X mental retardation protein (FMRP). Cortical pyramidal neurons in affected individuals and Fmr1 knock-out (KO) mice have an increased density of dendritic spines. The mutant mice also show defects in synaptic and experience-dependent circuit plasticity, which are known to be mediated in part by dendritic spine dynamics. We used in vivo time-lapse imaging with two-photon microscopy through cranial windows in male and female neonatal mice to test the hypothesis that dynamics of dendritic protrusions are altered in KO mice during early postnatal development. We find that layer 2/3 neurons from wild-type mice exhibit a rapid decrease in dendritic spine dynamics during the first 2 postnatal weeks, as immature filopodia are replaced by mushroom spines. In contrast, KO mice show a developmental delay in the downregulation of spine turnover and in the transition from immature to mature spine subtypes. Blockade of metabotropic glutamate receptor (mGluR) signaling, which reverses some adult phenotypes of KO mice, accentuated this immature protrusion phenotype in KO mice. Thus, absence of FMRP delays spine stabilization and dysregulated mGluR signaling in FXS may partially normalize this early synaptic defect.

Developmental biomechanics of the human cervical spine.

PubMed

Nuckley, David J; Linders, David R; Ching, Randal P

2013-04-05

Head and neck injuries, the leading cause of death for children in the U.S., are difficult to diagnose, treat, and prevent because of a critical void in our understanding of the biomechanical response of the immature cervical spine. The objective of this study was to investigate the functional and failure biomechanics of the cervical spine across multiple axes of loading throughout maturation. A correlational study design was used to examine the relationships governing spinal maturation and biomechanical flexibility curves and tolerance data using a cadaver human in vitro model. Eleven human cadaver cervical spines from across the developmental spectrum (2-28 years) were dissected into segments (C1-C2, C3-C5, and C6-C7) for biomechanical testing. Non-destructive flexibility tests were performed in tension, compression, flexion, extension, lateral bending, and axial rotation. After measuring their intact biomechanical responses, each segment group was failed in different modes to measure the tissue tolerance in tension (C1-C2), compression (C3-C5), and extension (C5-C6). Classical injury patterns were observed in all of the specimens tested. Both the functional (p<0.014) and failure (p<0.0001) mechanics exhibited significant relationships with age. Nonlinear flexibility curves described the functional response of the cervical spine throughout maturation and elucidated age, spinal level, and mode of loading specificity. These data support our understanding of the child cervical spine from a developmental perspective and facilitate the generation of injury prevention or management schema for the mitigation of child spine injuries and their deleterious effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ultrastructure of spines and associated terminals on brainstem neurons controlling auditory input

PubMed Central

Brown, M. Christian; Lee, Daniel J.; Benson, Thane E.

2013-01-01

Spines are unique cellular appendages that isolate synaptic input to neurons and play a role in synaptic plasticity. Using the electron microscope, we studied spines and their associated synaptic terminals on three groups of brainstem neurons: tensor tympani motoneurons, stapedius motoneurons, and medial olivocochlear neurons, all of which exert reflexive control of processes in the auditory periphery. These spines are generally simple in shape; they are infrequent and found on the somata as well as the dendrites. Spines do not differ in volume among the three groups of neurons. In all cases, the spines are associated with a synaptic terminal that engulfs the spine rather than abuts its head. The positions of the synapses are variable, and some are found at a distance from the spine, suggesting that the isolation of synaptic input is of diminished importance for these spines. Each group of neurons receives three common types of synaptic terminals. The type of terminal associated with spines of the motoneurons contains pleomorphic vesicles, whereas the type associated with spines of olivocochlear neurons contains large round vesicles. Thus, spine-associated terminals in the motoneurons appear to be associated with inhibitory processes but in olivocochlear neurons they are associated with excitatory processes. PMID:23602963

Instrumentation and fusion for congenital spine deformities.

PubMed

Hedequist, Daniel J

2009-08-01

A retrospective clinical review. To review the use of modern instrumentation of the spine for congenital spinal deformities. Spinal instrumentation has evolved since the advent of the Harrington rod. There is a paucity of literature, which discusses the use of modern spinal instrumentation in congenital spine deformity cases. This review focuses on modern instrumentation techniques for congenital scoliosis and kyphosis. A systematic review was performed of the literature to discuss spinal implant use for congenital deformities. Spinal instrumentation may be safely and effectively used in cases of congenital spinal deformity. Spinal surgeons taking care of children with congenital spine deformities need to be trained in all aspects of modern spinal instrumentation.

Exploring Mercury Tail

NASA Image and Video Library

2008-08-26

As the MESSENGER spacecraft approached Mercury, the UVVS field of view was scanned across the planet's exospheric "tail," which is produced by the solar wind pushing Mercury's exosphere (the planet's extremely thin atmosphere) outward. This figure, recently published in Science magazine, shows a map of the distribution of sodium atoms as they stream away from the planet (see PIA10396); red and yellow colors represent a higher abundance of sodium than darker shades of blue and purple, as shown in the colored scale bar, which gives the brightness intensity in units of kiloRayleighs. The escaping atoms eventually form a comet-like tail that extends in the direction opposite that of the Sun for many planetary radii. The small squares outlined in black correspond to individual measurements that were used to create the full map. These measurements are the highest-spatial-resolution observations ever made of Mercury's tail. In less than six weeks, on October 6, 2008, similar measurements will be made during MESSENGER's second flyby of Mercury. Comparing the measurements from the two flybys will provide an unprecedented look at how Mercury's dynamic exosphere and tail vary with time. Date Acquired: January 14, 2008. http://photojournal.jpl.nasa.gov/catalog/PIA11076

The Effect of Plasma Exposure on Tail Regeneration of Tadpoles Xenopus Laevis

NASA Astrophysics Data System (ADS)

June, Joyce; Rivie, Adonis; Ezuduemoih, Raphael; Menon, Jaishri; Martus, Kevin

2014-03-01

Wound healing requires a balanced combination of nutrients and growth factors for healing and tissue regeneration. The effect of plasma exposure on tail regeneration of tadpoles, Xenopus laevis is investigated. The exposure of the wound to the helium plasma immediately followed the amputation of 40% of the tail. Amputation of the tail initiates regeneration of spinal cord, muscle, notochord, skin and connective tissues. By 24 h, the wound was covered by wound epithelium and blastema was formed by day 5. There was increased angiogenesis in plasma exposed tail regenerate compared to the control following 5 d post amputation. Observed was an increase in NO production in the regenerate of plasma exposed tadpoles was derived from increased activity of nNOS and iNOS. Western blot analysis for vascular endothelial growth factor showed stronger bands for the protein in amputated tadpoles of both the groups. Analysis of the composition and characteristics of the plasma using optical emission spectroscopy indicates excited state species consisting of N2, N2+,and OH is present in the plasma. This study was supported, in part, by the NSF Grant 1040108.

The Internet as a communication tool for orthopedic spine fellowships in the United States.

PubMed

Silvestre, Jason; Guzman, Javier Z; Skovrlj, Branko; Overley, Samuel C; Cho, Samuel K; Qureshi, Sheeraz A; Hecht, Andrew C

2015-04-01

Orthopedic residents seeking additional training in spine surgery commonly use the Internet to manage their fellowship applications. Although studies have assessed the accessibility and content of Web sites in other medical specialties, none have looked at orthopedic spine fellowship Web sites (SFWs). The purpose of this study was to evaluate the accessibility of information from commonly used databases and assess the content of SFWs. This was a Web site accessibility and content evaluation study. A comprehensive list of available orthopedic spine fellowship programs was compiled by accessing program lists from the SF Match, North American Spine Society, Fellowship and Residency Electronic Interactive Database (FREIDA), and Orthopaedicsone.com (Ortho1). These databases were assessed for accessibility of information including viable links to SFWs and responsive program contacts. A Google search was used to identify SFWs not readily available on these national databases. SFWs were evaluated based on online education and recruitment content. Evaluators found 45 SFWs of 63 active programs (71%). Available SFWs were often not readily accessible from national program lists, and no program afforded a direct link to their SFW from SF Match. Approximately half of all programs responded via e-mail. Although many programs described surgical experience (91%) and research requirements (87%) during the fellowship, less than half mentioned didactic instruction (46%), journal clubs (41%), and national meetings or courses attended (28%). Evaluators found an average 45% of fellow recruitment content. Comparison of SFWs by program characteristics revealed three significant differences. Programs with greater than one fellowship position had greater online education content than programs with a single fellow (p=.022). Spine fellowships affiliated with an orthopedic residency program maintained greater education (p=.006) and recruitment (p=.046) content on their SFWs. Most orthopedic

Dual energy X-ray absorptiometry spine scans to determine abdominal fat in postmenopausal women.

PubMed

Bea, J W; Blew, R M; Going, S B; Hsu, C-H; Lee, M C; Lee, V R; Caan, B J; Kwan, M L; Lohman, T G

2016-11-01

Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n = 103). ROIs were (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and (3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N = 25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. Mean age, BMI, and total body fat were 66.1 ± 4.8 y, 25.8 ± 3.8 kg/m 2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R 2 : 0.83) and L2-IC (Adj. R 2 : 0.84) abdominal fat (%) well; the adjusted R 2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R 2 : 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat, respectively). The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in postmenopausal chronic disease risk prediction models. Am. J. Hum. Biol. 28:918-926, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Association Between Allogeneic Blood Transfusion and Postoperative Infection in Major Spine Surgery.

PubMed

Fisahn, Christian; Jeyamohan, Shiveindra; Norvell, Daniel C; Tubbs, Richard S; Moisi, Marc; Chapman, Jens R; Page, Jeni; Oskouian, Rod J

2017-08-01

Retrospective cohort study. The objective of this study is to compare the incidence of infection in patients who do and do not receive blood transfusions in major deformity surgery (>8 levels). Postoperative infections increase morbidity and mortality rates in spine surgery and generate additional costs for the health care system. It has been proposed that blood transfusions increase the risk of wound infection, urinary tract infection, pneumonia, and sepsis. A total of 56 patients met the study criteria, receiving spine surgery involving the fusion of 8 levels or more. Patient-specific characteristics, starting and ending hematocrits, number of units transfused and infections including urinary tract infection, wound infection, pneumonia, and sepsis were documented. Differences in infection risk between those who did and did not undergo a transfusion and their 95% confidence intervals were calculated. Groups were similar with respect to baseline and surgical characteristics except for smoking status, operative time, estimated blood loss, and ending hematocrit. The overall infection rate was greater in patients who underwent transfusion than those who did not (36% vs. 10%; P=0.03). Wound infections (n=5) were only observed in those who underwent a transfusion. Smokers were more likely to receive a transfusion and more likely to experience infection. A stratified analysis demonstrated an increased risk of infection associated with transfusion; however, the risk was greater in smokers, suggesting the effect of transfusion on infection could be modified by smoking. Patients undergoing transfusion experienced a significantly longer hospital stay (P=0.01). Allogeneic red blood cell transfusion in major spine surgery could be a risk factor for postoperative infection. This increased risk seems to be magnified in those who smoke. Further studies are warranted, and risks of blood loss and transfusion-related complications in smokers also potentially merit exploration. Level

Mu-opioid receptors modulate the stability of dendritic spines

PubMed Central

Liao, Dezhi; Lin, Hang; Law, Ping Yee; Loh, Horace H.

2005-01-01

Opioids classically regulate the excitability of neurons by suppressing synaptic GABA release from inhibitory neurons. Here, we report a role for opioids in modulating excitatory synaptic transmission. By activating ubiquitously clustered μ-opioid receptor (MOR) in excitatory synapses, morphine caused collapse of preexisting dendritic spines and decreased synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. Meanwhile, the opioid antagonist naloxone increased the density of spines. Chronic treatment with morphine decreased the density of dendritic spines even in the presence of Tetrodotoxin, a sodium channel blocker, indicating that the morphine's effect was not caused by altered activity in neural network through suppression of GABA release. The effect of morphine on dendritic spines was absent in transgenic mice lacking MORs and was blocked by CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-ThrNH2), a μ-receptor antagonist. These data together with others suggest that endogenous opioids and/or constitutive activity of MORs participate in maintaining normal morphology and function of spines, challenging the classical model of opioids. Abnormal alteration of spines may occur in drug addiction when opioid receptors are overactivated by exogenous opiates. PMID:15659552

[Distribution characteristics of soil nematodes in reclaimed land of copper-mine-tailings in different plant associations].

PubMed

Zhu, Yong-heng; Li, Ke-zhong; Zhang, Heng; Han, Fei; Zhou, Ju-hua; Gao, Ting-ting

2015-02-01

A survey was carried out to investigate soil nematode communities in the plant associations of gramineae (Arthraxon lanceolatus, AL; Imperata cylindrica, IC) and leguminosae (Glycine soja, GS) in reclaimed land of copper-mine-tailings and in the plant associations of gramineae (Digitaria chrysoblephara, DC-CK) of peripheral control in Fenghuang Mountain, Tongling City. A total of 1277 nematodes were extracted and sorted into 51 genera. The average individual density of the nematodes was 590 individuals · 100 g(-1) dry soil. In order to analyze the distribution character- istics of soil nematode communities in reclaimed land of copper-mine-tailings, Shannon community diversity index and soil food web structure indices were applied in the research. The results showed that the total number of nematode genus and the Shannon community diversity index of soil nematode in the three plant associations of AL, IC and GS were less than that in the plant associations of DC-CK. Compared with the ecological indices of soil nematode communities among the different plant associations in reclaimed land of copper-mine-tailings and peripheral natural habitat, we found that the structure of soil food web in the plant associations of GS was more mature, with bacterial decomposition being dominant in the soil organic matter decomposition, and that the soil ecosystem in the plant associations of GS was not stable with low interference. This indicated that the soil food web in the plant associations of leguminosae had a greater development potential to improve the ecological stability of the reclaimed land of copper-mine-tailings. On the other hand, the structure of soil food web in the plant associations of AL and IC were relatively stable in a structured state with fungal decomposition being dominant in the decomposition of soil organic matter. This indicated that the soil food web in the plant associations of gramineae was at a poor development level.

Accuracy of the Canadian C-spine rule and NEXUS to screen for clinically important cervical spine injury in patients following blunt trauma: a systematic review

PubMed Central

Michaleff, Zoe A.; Maher, Chris G.; Verhagen, Arianne P.; Rebbeck, Trudy; Lin, Chung-Wei Christine

2012-01-01

Background: There is uncertainty about the optimal approach to screen for clinically important cervical spine (C-spine) injury following blunt trauma. We conducted a systematic review to investigate the diagnostic accuracy of the Canadian C-spine rule and the National Emergency X-Radiography Utilization Study (NEXUS) criteria, 2 rules that are available to assist emergency physicians to assess the need for cervical spine imaging. Methods: We identified studies by an electronic search of CINAHL, Embase and MEDLINE. We included articles that reported on a cohort of patients who experienced blunt trauma and for whom clinically important cervical spine injury detectable by diagnostic imaging was the differential diagnosis; evaluated the diagnostic accuracy of the Canadian C-spine rule or NEXUS or both; and used an adequate reference standard. We assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies criteria. We used the extracted data to calculate sensitivity, specificity, likelihood ratios and post-test probabilities. Results: We included 15 studies of modest methodologic quality. For the Canadian C-spine rule, sensitivity ranged from 0.90 to 1.00 and specificity ranged from 0.01 to 0.77. For NEXUS, sensitivity ranged from 0.83 to 1.00 and specificity ranged from 0.02 to 0.46. One study directly compared the accuracy of these 2 rules using the same cohort and found that the Canadian C-spine rule had better accuracy. For both rules, a negative test was more informative for reducing the probability of a clinically important cervical spine injury. Interpretation: Based on studies with modest methodologic quality and only one direct comparison, we found that the Canadian C-spine rule appears to have better diagnostic accuracy than the NEXUS criteria. Future studies need to follow rigorous methodologic procedures to ensure that the findings are as free of bias as possible. PMID:23048086

Post-synaptic Density-95 (PSD-95) Binding Capacity of G-protein-coupled Receptor 30 (GPR30), an Estrogen Receptor That Can Be Identified in Hippocampal Dendritic Spines*

PubMed Central

Akama, Keith T.; Thompson, Louisa I.; Milner, Teresa A.; McEwen, Bruce S.

2013-01-01

The estrogen 17β-estradiol (E2) modulates dendritic spine plasticity in the cornu ammonis 1 (CA1) region of the hippocampus, and GPR30 (G-protein coupled estrogen receptor 1 (GPER1)) is an estrogen-sensitive G-protein-coupled receptor (GPCR) that is expressed in the mammalian brain and in specific subregions that are responsive to E2, including the hippocampus. The subcellular localization of hippocampal GPR30, however, remains unclear. Here, we demonstrate that GPR30 immunoreactivity is detected in dendritic spines of rat CA1 hippocampal neurons in vivo and that GPR30 protein can be found in rat brain synaptosomes. GPR30 immunoreactivity is identified at the post-synaptic density (PSD) and in the adjacent peri-synaptic zone, and GPR30 can associate with the spine scaffolding protein PSD-95 both in vitro and in vivo. This PSD-95 binding capacity of GPR30 is specific and determined by the receptor C-terminal tail that is both necessary and sufficient for PSD-95 interaction. The interaction with PSD-95 functions to increase GPR30 protein levels residing at the plasma membrane surface. GPR30 associates with the N-terminal tandem pair of PDZ domains in PSD-95, suggesting that PSD-95 may be involved in clustering GPR30 with other receptors in the hippocampus. We demonstrate that GPR30 has the potential to associate with additional post-synaptic GPCRs, including the membrane progestin receptor, the corticotropin releasing hormone receptor, and the 5HT1a serotonin receptor. These data demonstrate that GPR30 is well positioned in the dendritic spine compartment to integrate E2 sensitivity directly onto multiple inputs on synaptic activity and might begin to provide a molecular explanation as to how E2 modulates dendritic spine plasticity. PMID:23300088

Post-synaptic density-95 (PSD-95) binding capacity of G-protein-coupled receptor 30 (GPR30), an estrogen receptor that can be identified in hippocampal dendritic spines.

PubMed

Akama, Keith T; Thompson, Louisa I; Milner, Teresa A; McEwen, Bruce S

2013-03-01

The estrogen 17β-estradiol (E2) modulates dendritic spine plasticity in the cornu ammonis 1 (CA1) region of the hippocampus, and GPR30 (G-protein coupled estrogen receptor 1 (GPER1)) is an estrogen-sensitive G-protein-coupled receptor (GPCR) that is expressed in the mammalian brain and in specific subregions that are responsive to E2, including the hippocampus. The subcellular localization of hippocampal GPR30, however, remains unclear. Here, we demonstrate that GPR30 immunoreactivity is detected in dendritic spines of rat CA1 hippocampal neurons in vivo and that GPR30 protein can be found in rat brain synaptosomes. GPR30 immunoreactivity is identified at the post-synaptic density (PSD) and in the adjacent peri-synaptic zone, and GPR30 can associate with the spine scaffolding protein PSD-95 both in vitro and in vivo. This PSD-95 binding capacity of GPR30 is specific and determined by the receptor C-terminal tail that is both necessary and sufficient for PSD-95 interaction. The interaction with PSD-95 functions to increase GPR30 protein levels residing at the plasma membrane surface. GPR30 associates with the N-terminal tandem pair of PDZ domains in PSD-95, suggesting that PSD-95 may be involved in clustering GPR30 with other receptors in the hippocampus. We demonstrate that GPR30 has the potential to associate with additional post-synaptic GPCRs, including the membrane progestin receptor, the corticotropin releasing hormone receptor, and the 5HT1a serotonin receptor. These data demonstrate that GPR30 is well positioned in the dendritic spine compartment to integrate E2 sensitivity directly onto multiple inputs on synaptic activity and might begin to provide a molecular explanation as to how E2 modulates dendritic spine plasticity.

Ageing and degradation determines failure mode on sea urchin spines.

PubMed

Merino, Monica; Vicente, Erika; Gonzales, Karen N; Torres, Fernando G

2017-09-01

Sea urchin spines are an example of a hard natural composite with mineral and organic phases. The role of the organic phase in the response to mechanical stress was assessed by promoting the degradation of such spines by exposing them to ageing and ultraviolet (UV) irradiation. Thermal and structural characterization of the irradiated samples show that this UV irradiation treatment promotes degradation of the organic and inorganic phase of spines. Uniaxial compression tests carried out on aged and UV irradiated samples showed that both treatments affected the mechanical properties of the spines. Scanning electron microscopy (SEM) images of failed specimens were used to analyze the failure mechanisms of the compressed spines. The analysis of the fracture surfaces showed that the failure mechanisms of spines were modified as a consequence of UV irradiation, leading in the last case to mostly brittle fracture surfaces. We suggest that the proteins responsible for the formation of calcite also determine the mechanical properties and the failure mode of spines. This system can be used as a model for the study of the failure modes of other natural and synthetic hard composites. Copyright © 2017 Elsevier B.V. All rights reserved.

Tail-scope: Using friends to estimate heavy tails of degree distributions in large-scale complex networks

NASA Astrophysics Data System (ADS)

Eom, Young-Ho; Jo, Hang-Hyun

2015-05-01

Many complex networks in natural and social phenomena have often been characterized by heavy-tailed degree distributions. However, due to rapidly growing size of network data and concerns on privacy issues about using these data, it becomes more difficult to analyze complete data sets. Thus, it is crucial to devise effective and efficient estimation methods for heavy tails of degree distributions in large-scale networks only using local information of a small fraction of sampled nodes. Here we propose a tail-scope method based on local observational bias of the friendship paradox. We show that the tail-scope method outperforms the uniform node sampling for estimating heavy tails of degree distributions, while the opposite tendency is observed in the range of small degrees. In order to take advantages of both sampling methods, we devise the hybrid method that successfully recovers the whole range of degree distributions. Our tail-scope method shows how structural heterogeneities of large-scale complex networks can be used to effectively reveal the network structure only with limited local information.

Epidural Hematoma Following Cervical Spine Surgery.

PubMed

Schroeder, Gregory D; Hilibrand, Alan S; Arnold, Paul M; Fish, David E; Wang, Jeffrey C; Gum, Jeffrey L; Smith, Zachary A; Hsu, Wellington K; Gokaslan, Ziya L; Isaacs, Robert E; Kanter, Adam S; Mroz, Thomas E; Nassr, Ahmad; Sasso, Rick C; Fehlings, Michael G; Buser, Zorica; Bydon, Mohamad; Cha, Peter I; Chatterjee, Dhananjay; Gee, Erica L; Lord, Elizabeth L; Mayer, Erik N; McBride, Owen J; Nguyen, Emily C; Roe, Allison K; Tortolani, P Justin; Stroh, D Alex; Yanez, Marisa Y; Riew, K Daniel

2017-04-01

A multicentered retrospective case series. To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine. Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified. A total of 16 582 cervical spine surgeries were identified, and 15 patients developed a postoperative epidural hematoma, for a total incidence of 0.090%. Substantial variation between institutions was noted, with 11 sites reporting no epidural hematomas, and 1 site reporting an incidence of 0.76%. All patients initially presented with a neurologic deficit. Nine patients had complete resolution of the neurologic deficit after hematoma evacuation; however 2 of the 3 patients (66%) who had a delay in the diagnosis of the epidural hematoma had residual neurologic deficits compared to only 4 of the 12 patients (33%) who had no delay in the diagnosis or treatment ( P = .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation. This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements.

Early predictors of lumbar spine surgery after occupational back injury: results from a prospective study of workers in Washington State.

PubMed

Keeney, Benjamin J; Fulton-Kehoe, Deborah; Turner, Judith A; Wickizer, Thomas M; Chan, Kwun Chuen Gary; Franklin, Gary M

2013-05-15

Prospective population-based cohort study. To identify early predictors of lumbar spine surgery within 3 years after occupational back injury. Back injuries are the most prevalent occupational injury in the United States. Few prospective studies have examined early predictors of spine surgery after work-related back injury. Using Disability Risk Identification Study Cohort (D-RISC) data, we examined the early predictors of lumbar spine surgery within 3 years among Washington State workers, with new workers compensation temporary total disability claims for back injuries. Baseline measures included worker-reported measures obtained approximately 3 weeks after claim submission. We used medical bill data to determine whether participants underwent surgery, covered by the claim, within 3 years. Baseline predictors (P < 0.10) of surgery in bivariate analyses were included in a multivariate logistic regression model predicting lumbar spine surgery. The area under the receiver operating characteristic curve of the model was used to determine the model's ability to identify correctly workers who underwent surgery. In the D-RISC sample of 1885 workers, 174 (9.2%) had a lumbar spine surgery within 3 years. Baseline variables associated with surgery (P < 0.05) in the multivariate model included higher Roland-Morris Disability Questionnaire scores, greater injury severity, and surgeon as first provider seen for the injury. Reduced odds of surgery were observed for those younger than 35 years, females, Hispanics, and those whose first provider was a chiropractor. Approximately 42.7% of workers who first saw a surgeon had surgery, in contrast to only 1.5% of those who saw a chiropractor. The area under the receiver operating characteristic curve of the multivariate model was 0.93 (95% confidence interval, 0.92-0.95), indicating excellent ability to discriminate between workers who would versus would not have surgery. Baseline variables in multiple domains predicted lumbar spine

Does climate have heavy tails?

NASA Astrophysics Data System (ADS)

Bermejo, Miguel; Mudelsee, Manfred

2013-04-01

When we speak about a distribution with heavy tails, we are referring to the probability of the existence of extreme values will be relatively large. Several heavy-tail models are constructed from Poisson processes, which are the most tractable models. Among such processes, one of the most important are the Lévy processes, which are those process with independent, stationary increments and stochastic continuity. If the random component of a climate process that generates the data exhibits a heavy-tail distribution, and if that fact is ignored by assuming a finite-variance distribution, then there would be serious consequences (in the form, e.g., of bias) for the analysis of extreme values. Yet, it appears that it is an open question to what extent and degree climate data exhibit heavy-tail phenomena. We present a study about the statistical inference in the presence of heavy-tail distribution. In particular, we explore (1) the estimation of tail index of the marginal distribution using several estimation techniques (e.g., Hill estimator, Pickands estimator) and (2) the power of hypothesis tests. The performance of the different methods are compared using artificial time-series by means of Monte Carlo experiments. We systematically apply the heavy tail inference to observed climate data, in particular we focus on time series data. We study several proxy and directly observed climate variables from the instrumental period, the Holocene and the Pleistocene. This work receives financial support from the European Commission (Marie Curie Initial Training Network LINC, No. 289447, within the 7th Framework Programme).

Electrical and Ca2+ signaling in dendritic spines of substantia nigra dopaminergic neurons

PubMed Central

Hage, Travis A; Sun, Yujie; Khaliq, Zayd M

2016-01-01

Little is known about the density and function of dendritic spines on midbrain dopamine neurons, or the relative contribution of spine and shaft synapses to excitability. Using Ca2+ imaging, glutamate uncaging, fluorescence recovery after photobleaching and transgenic mice expressing labeled PSD-95, we comparatively analyzed electrical and Ca2+ signaling in spines and shaft synapses of dopamine neurons. Dendritic spines were present on dopaminergic neurons at low densities in live and fixed tissue. Uncaging-evoked potential amplitudes correlated inversely with spine length but positively with the presence of PSD-95. Spine Ca2+ signals were less sensitive to hyperpolarization than shaft synapses, suggesting amplification of spine head voltages. Lastly, activating spines during pacemaking, we observed an unexpected enhancement of spine Ca2+ midway throughout the spike cycle, likely involving recruitment of NMDA receptors and voltage-gated conductances. These results demonstrate functionality of spines in dopamine neurons and reveal a novel modulation of spine Ca2+ signaling during pacemaking. DOI: http://dx.doi.org/10.7554/eLife.13905.001 PMID:27163179

Design-Based Comparison of Spine Surgery Simulators: Optimizing Educational Features of Surgical Simulators.

PubMed

Ryu, Won Hyung A; Mostafa, Ahmed E; Dharampal, Navjit; Sharlin, Ehud; Kopp, Gail; Jacobs, W Bradley; Hurlbert, R John; Chan, Sonny; Sutherland, Garnette R

2017-10-01

Simulation-based education has made its entry into surgical residency training, particularly as an adjunct to hands-on clinical experience. However, one of the ongoing challenges to wide adoption is the capacity of simulators to incorporate educational features required for effective learning. The aim of this study was to identify strengths and limitations of spine simulators to characterize design elements that are essential in enhancing resident education. We performed a mixed qualitative and quantitative cohort study with a focused survey and interviews of stakeholders in spine surgery pertaining to their experiences on 3 spine simulators. Ten participants were recruited spanning all levels of training and expertise until qualitative analysis reached saturation of themes. Participants were asked to perform lumbar pedicle screw insertion on 3 simulators. Afterward, a 10-item survey was administrated and a focused interview was conducted to explore topics pertaining to the design features of the simulators. Overall impressions of the simulators were positive with regards to their educational benefit, but our qualitative analysis revealed differing strengths and limitations. Main design strengths of the computer-based simulators were incorporation of procedural guidance and provision of performance feedback. The synthetic model excelled in achieving more realistic haptic feedback and incorporating use of actual surgical tools. Stakeholders from trainees to experts acknowledge the growing role of simulation-based education in spine surgery. However, different simulation modalities have varying design elements that augment learning in distinct ways. Characterization of these design characteristics will allow for standardization of simulation curricula in spinal surgery, optimizing educational benefit. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of density-of-state tails on band-to-band tunneling: Theory and application to tunnel field effect transistors

NASA Astrophysics Data System (ADS)

Sant, S.; Schenk, A.

2017-10-01

It is demonstrated how band tail states in the semiconductor influence the performance of a Tunnel Field Effect Transistor (TFET). As a consequence of the smoothened density of states (DOS) around the band edges, the energetic overlap of conduction and valence band states occurs gradually at the onset of band-to-band tunneling (BTBT), thus degrading the sub-threshold swing (SS) of the TFET. The effect of the band tail states on the current-voltage characteristics is modelled quantum-mechanically based on the idea of zero-phonon trap-assisted tunneling between band and tail states. The latter are assumed to arise from a 3-dimensional pseudo-delta potential proposed by Vinogradov [1]. This model potential allows the derivation of analytical expressions for the generation rate covering the whole range from very strong to very weak localization of the tail states. Comparison with direct BTBT in the one-band effective mass approximation reveals the essential features of tail-to-band tunneling. Furthermore, an analytical solution for the problem of tunneling from continuum states of the disturbed DOS to states in the opposite band is found, and the differences to direct BTBT are worked out. Based on the analytical expressions, a semi-classical model is implemented in a commercial device simulator which involves numerical integration along the tunnel paths. The impact of the tail states on the device performance is analyzed for a nanowire Gate-All-Around TFET. The simulations show that tail states notably impact the transfer characteristics of a TFET. It is found that exponentially decaying band tails result in a stronger degradation of the SS than tail states with a Gaussian decay of their density. The developed model allows more realistic simulations of TFETs including their non-idealities.

The Tail of BPM

NASA Astrophysics Data System (ADS)

Kruba, Steve; Meyer, Jim

Business process management suites (BPMS's) represent one of the fastest growing segments in the software industry as organizations automate their key business processes. As this market matures, it is interesting to compare it to Chris Anderson's 'Long Tail.' Although the 2004 "Long Tail" article in Wired magazine was primarily about the media and entertainment industries, it has since been applied (and perhaps misapplied) to other markets. Analysts describe a "Tail of BPM" market that is, perhaps, several times larger than the traditional BPMS product market. This paper will draw comparisons between the concepts in Anderson's article (and subsequent book) and the BPM solutions market.

Altitude Performance Characteristics of Turbojet-engine Tail-pipe Burner with Variable-area Exhaust Nozzle Using Several Fuel Systems and Flame Holders

NASA Technical Reports Server (NTRS)

Johnson, Lavern A; Meyer, Carl L

1950-01-01

A tail-pipe burner with a variable-area exhaust nozzle was investigated. From five configurations a fuel-distribution system and a flame holder were selected. The best configuration was investigated over a range of altitudes and flight Mach numbers. For the best configuration, an increase in altitude lowered the augmented thrust ratio, exhaust-gas total temperature, and tail-pipe combustion efficiency, and raised the specific fuel consumption. An increase in flight Mach number raised the augmented thrust ratio but had no apparent effect on exhaust-gas total temperature, tail-pipe combustion efficiency, or specific fuel consumption.

RSA in Spine: A Review.

PubMed

Humadi, Ali; Dawood, Sulaf; Halldin, Klas; Freeman, Brian

2017-12-01

Systematic review of literature. This systematic review was conducted to investigate the accuracy of radiostereometric analysis (RSA), its assessment of spinal motion and disorders, and to investigate the limitations of this technique in spine assessment. Systematic review in all current literature to invesigate the role of RSA in spine. The results of this review concluded that RSA is a very powerful tool to detect small changes between 2 rigid bodies such as a vertebral segment. The technique is described for animal and human studies for cervical and lumbar spine and can be used to analyze range of motion, inducible displacement, and fusion of segments. However, there are a few disadvantages with the technique; RSA percutaneous procedure needs to be performed to implant the markers (and cannot be used preoperatively), one needs a specific knowledge to handle data and interpret the results, and is relatively time consuming and expensive. RSA should be looked at as a very powerful research instrument and there are many questions suitable for RSA studies.

RSA in Spine: A Review

PubMed Central

Dawood, Sulaf; Halldin, Klas; Freeman, Brian

2017-01-01

Study Design: Systematic review of literature. Objectives: This systematic review was conducted to investigate the accuracy of radiostereometric analysis (RSA), its assessment of spinal motion and disorders, and to investigate the limitations of this technique in spine assessment. Methods: Systematic review in all current literature to invesigate the role of RSA in spine. Results: The results of this review concluded that RSA is a very powerful tool to detect small changes between 2 rigid bodies such as a vertebral segment. The technique is described for animal and human studies for cervical and lumbar spine and can be used to analyze range of motion, inducible displacement, and fusion of segments. However, there are a few disadvantages with the technique; RSA percutaneous procedure needs to be performed to implant the markers (and cannot be used preoperatively), one needs a specific knowledge to handle data and interpret the results, and is relatively time consuming and expensive. Conclusions: RSA should be looked at as a very powerful research instrument and there are many questions suitable for RSA studies. PMID:29238647

Introductory tail-flick of the Jacky dragon visual display: signal efficacy depends upon duration.

PubMed

Peters, Richard A; Evans, Christopher S

2003-12-01

Many animal signals have introductory components that alert receivers. Examples from the acoustic and visual domains show that this effect is often achieved with high intensity, a simple structure and a short duration. Quantitative analyses of the Jacky dragon Amphibolurus muricatus visual display reveal a different design: the introductory tail-flick has a lower velocity than subsequent components of the signal, but a longer duration. Here, using a series of video playback experiments with a digitally animated tail, we identify the properties responsible for signal efficacy. We began by validating the use of the computer-generated tail, comparing the responses to digital video footage of a lizard tail-flick with those to a precisely matched 3-D animation (Experiment 1). We then examined the effects of variation in stimulus speed, acceleration, duration and period by expanding and compressing the time scale of the sequence (Experiment 2). The results identified several variables that might mediate recognition. Two follow-up studies assessed the importance of tail-flick amplitude (Experiment 3), movement speed and signal duration (Experiment 4). Lizard responses to this array of stimuli reveal that duration is the most important characteristic of the tail-flick, and that intermittent signalling has the same effect as continuous movement. We suggest that signal design may reflect a trade-off between efficacy and cost.

Primary telangiectatic osteosarcoma of the cervical spine.

PubMed

Turel, Mazda K; Joseph, Vivek; Singh, Vandita; Moses, Vinu; Rajshekhar, Vedantam

2012-04-01

Telangiectatic osteosarcoma (TOS) is one of the 8 subtypes of osteosarcoma that infrequently affects the spine. The radiopathological features of TOS overlap with those of more benign entities, most commonly the aneurysmal bone cyst), and therefore is a significant diagnostic challenge. It is a rare but well-described entity in the thoracolumbar and sacral spine, and to the authors' knowledge has not been previously reported in the cervical spine. The authors report the case of a 15-year-old boy who presented with a 6-month history of neck pain and torticollis. He underwent preoperative glue embolization followed by a staged subtotal C-5 spondylectomy and posterior fusion for a C-5 vertebral body lytic expansile lesion. Histopathological examination showed the lesion to be TOS. The surgery was followed by adjuvant radiation and chemotherapy with a favorable outcome at the 1-year follow-up. This report reiterates that TOS is an important differential diagnosis for aneurysmal bone cyst and giant-cell tumor of the spine, as its biological behavior and clinical outcome differ from those of these more benign lesions, which it mimics.

Stably maintained dendritic spines are associated with lifelong memories

PubMed Central

Yang, Guang; Pan, Feng; Gan, Wen-Biao

2016-01-01

Changes in synaptic connections are considered essential for learning and memory formation1–6. However, it is unknown how neural circuits undergo continuous synaptic changes during learning while maintaining lifelong memories. Here we show, by following postsynaptic dendritic spines over time in the mouse cortex7–8, that learning and novel sensory experience lead to spine formation and elimination by a protracted process. The extent of spine remodelling correlates with behavioural improvement after learning, suggesting a crucial role of synaptic structural plasticity in memory formation and storage. Importantly, a small fraction of new spines induced by novel experience, together with most spines formed early during development and surviving experience-dependent elimination, are preserved throughout the entire life of an animal. These studies indicate that learning and daily sensory experience leave minute but permanent marks on cortical connections and suggest that lifelong memories are stored in largely stably connected synaptic networks. PMID:19946265

Epithelioid hemangioma of the spine: Two cases.

PubMed

O'Shea, Bendan M; Kim, Jinsuh

2014-01-01

We report two cases of epithelioid hemangioma (EH) manifested in the thoracic spine with associated clinical, radiographic, and pathological findings. Epithelioid hemangioma is a benign vascular tumor that can involve any bone (including the spine in a subset of patients). Although recognized as a benign tumor by the WHO, it can display locally aggressive features. Within the spine, these features may lead to pain, instability, and/or neurologic dysfunction. The radiographic appearance is most typically that of a lytic, well-defined lesion on plain film or CT. The MRI appearance is typically hypointense on T1WI, hyperintense on T2WI, and avidly enhancing, often with an extraosseous soft-tissue component.

Cervical Spine Injuries in Children Associated With Sports and Recreational Activities.

PubMed

Babcock, Lynn; Olsen, Cody S; Jaffe, David M; Leonard, Julie C

2016-09-30

The aim of this study was to ascertain potential factors associated with cervical spine injuries in children injured during sports and recreational activities. This is a secondary analysis of a multicenter retrospective case-control study involving children younger than 16 years who presented to emergency departments after blunt trauma and underwent cervical spine radiography. Cases had cervical spine injury from sports or recreational activities (n = 179). Comparison groups sustained (1) cervical spine injury from other mechanisms (n = 361) or (2) other injuries from sports and recreational activities but were free of cervical spine injury (n = 180). For children with sport and recreational activity-related cervical spine injuries, common injury patterns were subaxial (49%) and fractures (56%). These children were at increased odds of spinal cord injury without radiographic abnormalities compared with children with cervical spine injuries from other mechanisms (25% vs 6%). Children with sport and recreational activity-related trauma had increased odds of cervical spine injury if they had focal neurologic findings (odds ratio [OR], 5.7; 95% confidence interval [CI], 3.5-9.4), had complaints of neck pain (OR, 3.1; 95% CI, 1.9-5.0), were injured diving (OR, 43.5; 95% CI, 5.9-321.3), or sustained axial loading impacts (OR, 2.2; 95% CI, 1.3-3.5). Football (22%), diving (20%), and bicycle crashes (11%) were the leading activities associated with cervical spine injury. In children injured during sports and recreational activities, focal neurologic findings, neck pain, axial loading impacts, and the possibility of spinal cord injury without radiographic abnormality should guide the diagnostic evaluation for potential cervical spine injuries. Certain activities have a considerable frequency of cervical spine injury, which may benefit from activity-specific preventive measures.

Cervical Spine Imaging in Hospitalized Children with Traumatic Brain Injury

PubMed Central

Bennett, Tellen D.; Bratton, Susan L.; Riva-Cambrin, Jay; Scaife, Eric R.; Nance, Michael L.; Prince, Jeffrey S.; Wilkes, Jacob; Keenan, Heather T.

2015-01-01

Objectives In children with TBI, to describe cervical spine imaging practice, to assess for recent changes in imaging practice, and to determine if cervical spine CT is being used in children at low risk for cervical spine injury. Methods The setting was children’s hospitals participating in the Pediatric Health Information System database, January, 2001 to June, 2011. Participants were children (age < 18 years) with TBI who were evaluated in the Emergency Department, admitted to the hospital, and received a head CT scan on the day of admission. The primary outcome measures were cervical spine imaging studies. This study was exempted from IRB review. Results 30,112 children met study criteria. Overall, 52% (15,687/30,112) received cervical spine imaging. Use of cervical spine radiographs alone decreased between 2001 (47%) and 2011 (23%), annual decrease 2.2% (95% confidence interval [CI] 1.1–3.3%), largely replaced by increased use of CT, with or without radiographs (8.6% in 2001, 19.5% in 2011, annual increase 0.9%, 95% CI 0.1–1.8%). 2,545 children received a cervical spine CT despite being discharged alive from the hospital in < 72 hours, and 1,655 of those had a low-risk mechanism of injury. Conclusions The adoption of CT clearance of the cervical spine in adults appears to have influenced the care of children with TBI, despite concerns about radiation exposure. PMID:25803749

Historical contributions from the Harvard system to adult spine surgery.

PubMed

Schoenfeld, Andrew J

2011-10-15

Literature review. To document the historical contributions from the Harvard Medical School system to the field of adult spine surgery. Despite the fact that significant contributions to the discipline of spinal surgery have derived from the Harvard system, no prior study documents the history of the Harvard spine services in a cohesive narrative. This historical perspective reviews the history of adult spine surgery within the Harvard system and outlines the significant contributions made by orthopedic and neurosurgical practitioners to the field. Literature reviews were performed from historical works, as well as scientific publications to fashion a cohesive review covering the history of spine surgery at Harvard from the early 19th century to the present. The development of the spine surgical services at the three main Harvard hospitals, and significant spine surgical personalities within the system, are discussed, including W. Jason Mixter, MD, Joseph S. Barr Sr., MD, and Marius N. Smith-Petersen, MD. Substantial developments that have arisen from the Harvard teaching hospitals include the recognition of disc herniation as the cause of radicular symptoms in the lower extremities, the description of lumbar discectomy as a surgical treatment for radicular pain, osteotomy for the correction of spinal deformity, and the first attempt to create a systematic algorithm capable of informing treatment for cervical spine trauma. Despite humble beginnings, the surgeons and scientists at Harvard have influenced nearly every facet of spine surgery over the course of the last two centuries.

Active tails enhance arboreal acrobatics in geckos

PubMed Central

Jusufi, Ardian; Goldman, Daniel I.; Revzen, Shai; Full, Robert J.

2008-01-01

Geckos are nature's elite climbers. Their remarkable climbing feats have been attributed to specialized feet with hairy toes that uncurl and peel in milliseconds. Here, we report that the secret to the gecko's arboreal acrobatics includes an active tail. We examine the tail's role during rapid climbing, aerial descent, and gliding. We show that a gecko's tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle's kickstand. Should a gecko fall with its back to the ground, a swing of its tail induces the most rapid, zero-angular momentum air-righting response yet measured. Once righted to a sprawled gliding posture, circular tail movements control yaw and pitch as the gecko descends. Our results suggest that large, active tails can function as effective control appendages. These results have provided biological inspiration for the design of an active tail on a climbing robot, and we anticipate their use in small, unmanned gliding vehicles and multisegment spacecraft. PMID:18347344

Determination of the Oswestry Disability Index score equivalent to a "satisfactory symptom state" in patients undergoing surgery for degenerative disorders of the lumbar spine-a Spine Tango registry-based study.

PubMed

van Hooff, Miranda L; Mannion, Anne F; Staub, Lukas P; Ostelo, Raymond W J G; Fairbank, Jeremy C T

2016-10-01

The achievement of a given change score on a valid outcome instrument is commonly used to indicate whether a clinically relevant change has occurred after spine surgery. However, the achievement of such a change score can be dependent on baseline values and does not necessarily indicate whether the patient is satisfied with the current state. The achievement of an absolute score equivalent to a patient acceptable symptom state (PASS) may be a more stringent measure to indicate treatment success. This study aimed to estimate the score on the Oswestry Disability Index (ODI, version 2.1a; 0-100) corresponding to a PASS in patients who had undergone surgery for degenerative disorders of the lumbar spine. This is a cross-sectional study of diagnostic accuracy using follow-up data from an international spine surgery registry. The sample includes 1,288 patients with degenerative lumbar spine disorders who had undergone elective spine surgery, registered in the EUROSPINE Spine Tango Spine Surgery Registry. The main outcome measure was the ODI (version 2.1a). Surgical data and data from the ODI and Core Outcome Measures Index (COMI) were included to determine the ODI threshold equivalent to PASS at 1 year (±1.5 months; n=780) and 2 years (±2 months; n=508) postoperatively. The symptom-specific well-being item of the COMI was used as the external criterion in the receiver operating characteristic (ROC) analysis to determine the ODI threshold equivalent to PASS. Separate sensitivity analyses were performed based on the different definitions of an "acceptable state" and for subgroups of patients. JF is a copyright holder of the ODI. The ODI threshold for PASS was 22, irrespective of the time of follow-up (area under the curve [AUC]: 0.89 [sensitivity {Se}: 78.3%, specificity {Sp}: 82.1%] and AUC: 0.91 [Se: 80.7%, Sp: 85.6] for the 1- and 2-year follow-ups, respectively). Sensitivity analyses showed that the absolute ODI-22 threshold for the two follow-up time-points were

The management of hand injuries caused by sea urchin spines.

PubMed

Nassab, R; Rayatt, S; Peart, F

2005-08-01

Injuries to the hand by sea urchin spines are not commonly seen in the United Kingdom. There are many varieties of sea urchins (Echinoidea) throughout the world. They have a spherical calcium carbonate exoskeleton covered with spines. Certain varieties may be venomous, in particular the flower urchin (Toxopneustes pileolus) found in the Indo-Pacific oceans. Injury may also be caused by the urchin spines or pedicellaria (delicate seizing organs equipped with jaws). A small number of hand injuries associated with sea urchin spines have been reported in the literature.

The Rac-GAP alpha2-chimaerin regulates hippocampal dendrite and spine morphogenesis.

PubMed

Valdez, Chris M; Murphy, Geoffrey G; Beg, Asim A

2016-09-01

Dendritic spines are fine neuronal processes where spatially restricted input can induce activity-dependent changes in one spine, while leaving neighboring spines unmodified. Morphological spine plasticity is critical for synaptic transmission and is thought to underlie processes like learning and memory. Significantly, defects in dendritic spine stability and morphology are common pathogenic features found in several neurodevelopmental and neuropsychiatric disorders. The remodeling of spines relies on proteins that modulate the underlying cytoskeleton, which is primarily composed of filamentous (F)-actin. The Rho-GTPase Rac1 is a major regulator of F-actin and is essential for the development and plasticity of dendrites and spines. However, the key molecules and mechanisms that regulate Rac1-dependent pathways at spines and synapses are not well understood. We have identified the Rac1-GTPase activating protein, α2-chimaerin, as a critical negative regulator of Rac1 in hippocampal neurons. The loss of α2-chimaerin significantly increases the levels of active Rac1 and induces the formation of aberrant polymorphic dendritic spines. Further, disruption of α2-chimaerin signaling simplifies dendritic arbor complexity and increases the presence of dendritic spines that appear poly-innervated. Our data suggests that α2-chimaerin serves as a "brake" to constrain Rac1-dependent signaling to ensure that the mature morphology of spines is maintained in response to network activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Rib-based Distraction Surgery Maintains Total Spine Growth.

PubMed

El-Hawary, Ron; Samdani, Amer; Wade, Jennie; Smith, Melissa; Heflin, John A; Klatt, Joshua W; Vitale, Michael G; Smith, John T

2016-12-01

For children undergoing treatment of early onset scoliosis (EOS) using spine-based distraction, recently published research would suggest that total spine length (T1-S1) achieved after the initial lengthening procedure decreases with each subsequent lengthening. Our purpose was to evaluate the effect of rib-based distraction on spine growth in children with EOS. This was a retrospective multi-center review of 35 patients treated with rib-based distraction (minimum 5 y follow-up). Radiographs were analyzed at initial implantation and just before each subsequent lengthening. The primary outcome was T1-S1 height, which was also analyzed as: Change in T1-S1 height per lengthening procedure, percent of expected age-based T1-S1 growth per lengthening time interval, percent increase in T1-S1 height as compared with postimplantation total spine height, and percent of expected T1-S1 growth based upon patient age at time of lengthening procedure. Thirty-five patients with a mean age of 2.6 years at initial surgery were studied. Diagnoses included congenital (n=18), syndromic (n=7), idiopathic (n=5), and neuromuscular (n=5). Major Cobb angle was 63.5 degrees and kyphosis was 40.5 degree. Four postoperative time periods were compared: L1 (preoperative first lengthening surgery), L2-L5 (preoperative second lengthening to preoperative fifth lengthening), L6-L10 (preoperative sixth lengthening to preoperative 10th lengthening), L11-L15 (preoperative 11th lengthening to preoperative 15th lengthening). Cobb angle stayed relatively constant for each lengthening period while maximum kyphosis increased. Total spine height was 19.9 cm pre-implantation, 22.1 cm postimplantation, and 28.0 cm by the 15th lengthening (P<0.05). Percent expected T1-S1 growth per lengthening was 62% for L2-L5, 95% for L6-L10, and 52% for L11-L15. As compared with postimplantation spine height, over the course of 15 lengthening procedures, a further 27% increase in spine height was observed. When lengthening

Total vertebrectomy and spine shortening for the treatment of T12-L1 spine dislocation: Management with suboptimal resources.

PubMed

Lorente, Alejandro; Palacios, Pablo; Burgos, Jesús; Barrios, Carlos; Lorente, Rafael

2018-04-21

Total vertebrectomy with spine shortening has been reported for the treatment of difficult cases of traumatic spine dislocation, both in acute and chronic phase. We report an exceptional case of a five-week-old T12-L1 spine dislocation in a 25-year-old female with complete paraplegia as a result of trauma in Ciudad de León (Nicaragua). In view of the time since the dislocation, we performed a complete L1 vertebrectomy in order to reduce the dorsolumbar hinge. For osteosynthesis material we had only eight screws and two Steffee plates. We therefore introduced pedicle screws at levels T11, T12, L2 and L3 on the right side and T11, T12, L3 and L4 on the left, and performed manual reduction of the spine. Steffee plates were placed and we added sublaminar wires to reinforce the osteosynthesis. Fifteen months after surgery, there has been no neurological improvement. Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Three Cases of Spine Fractures after an Airplane Crash.

PubMed

Lee, Han Joo; Moon, Bong Ju; Pennant, William A; Shin, Dong Ah; Kim, Keung Nyun; Yoon, Do Heum; Ha, Yoon

2015-10-01

While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings.

Three Cases of Spine Fractures after an Airplane Crash

PubMed Central

Lee, Han Joo; Moon, Bong Ju; Pennant, William A.; Shin, Dong Ah; Kim, Keung Nyun; Yoon, Do Heum

2015-01-01

While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings. PMID:27169094

Precision and accuracy of age estimates obtained from anal fin spines, dorsal fin spines, and sagittal otoliths for known-age largemouth bass

USGS Publications Warehouse

Klein, Zachary B.; Bonvechio, Timothy F.; Bowen, Bryant R.; Quist, Michael C.

2017-01-01

Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Ocmulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species.

Comparison of the breeding biology of sympatric red-tailed Hawks, White-tailed Hawks, and Crested Caracaras in south Texas

USGS Publications Warehouse

Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

2009-01-01

We compared the breeding biology of sympatric nesting Red-tailed Hawks (Buteo jamaicensis), White-tailed Hawks (Buteo albicaudatus), and Crested Caracaras (Caracara cheriway) in south Texas during 2003 and 2004. We monitored 46 breeding attempts by Red-tailed Hawks, 56 by White-tailed Hawks, and 27 by Crested Caracaras. Observed nesting success was similar for Red-tailed Hawks (62%) and Crested Caracaras (61%), but lower for White-tailed Hawks (51%). Daily survival rates (0.99) were the same for all three species. Red-tailed Hawks and White-tailed Hawks both fledged 1.13 young per nesting pair and Crested Caracaras fledged 1.39 young per nesting pair. All three species nested earlier in 2004 than in 2003; in addition, the overall nesting density of these three species almost doubled from 2003 (1.45 pairs/km2) to 2004 (2.71 pairs/km2). Estimated productivity of all three species was within the ranges reported from other studies. Given extensive and progressive habitat alteration in some areas of south Texas, and the limited distributions of White-tailed Hawks and Crested Caracaras, the presence of large ranches managed for free-range cattle production and hunting leases likely provides important habitat and may be key areas for conservation of these two species. ?? 2009 The Raptor Research Foundation, Inc.

Posteroanterior versus anteroposterior lumbar spine radiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuno, M.M.; Shu, G.J.

The posteroanterior view of the lumbar spine has important features including radiation protection and image quality; these have been studied by various investigators. Investigators have shown that sensitive tissues receive less radiation dosage in the posteroanterior view of the spine for scoliosis screening and intracranial tomography without altering the image quality. This paper emphasizes the importance of the radiation safety aspect of the posteroanterior view and shows the improvement in shape distortion in the lumbar vertebrae.

Atmospheric pressure plasma accelerates tail regeneration in tadpoles Xenopus laevis

NASA Astrophysics Data System (ADS)

Rivie, A.; Martus, K.; Menon, J.

2017-08-01

Atmospheric pressure plasma is a partially ionized gas composed of neutral and charged particles, including electrons and ions, as well as reactive oxygen species (ROS). Recently, it is utilized as possible therapy in oncology, sterilization, skin diseases, wound healing and tissue regeneration. In this study we focused on effect of plasma exposure on tail regeneration of tadpoles, Xenopus leavis with special emphasis on role of ROS, antioxidant defenses and morphological features of the regenerate. When amputated region of the tail was exposed to the helium plasma it resulted in a faster rate of growth, elevated ROS and increase in antioxidant enzymes in the regenerate compared to that of untreated control. An increase in nitric oxide (free radical) as well as activity of nitric oxide synthase(s) were observed once the cells of the regeneration blastema - a mass of proliferating cells are ready for differentiation. Microscopically the cells of the regenerate of plasma treated tadpoles show altered morphology and characteristics of cellular hypoxia and oxidative stress. We summarize that plasma exposure accelerates the dynamics of wound healing and tail regeneration through its effects on cell proliferation and differentiation as well as angiogenesis mediated through ROS signaling.

Positioning patients for spine surgery: Avoiding uncommon position-related complications

PubMed Central

Kamel, Ihab; Barnette, Rodger

2014-01-01

Positioning patients for spine surgery is pivotal for optimal operating conditions and operative-site exposure. During spine surgery, patients are placed in positions that are not physiologic and may lead to complications. Perioperative peripheral nerve injury (PPNI) and postoperative visual loss (POVL) are rare complications related to patient positioning during spine surgery that result in significant patient disability and functional loss. PPNI is usually due to stretch or compression of the peripheral nerve. PPNI may present as a brachial plexus injury or as an isolated injury of single nerve, most commonly the ulnar nerve. Understanding the etiology, mechanism and pattern of injury with each type of nerve injury is important for the prevention of PPNI. Intraoperative neuromonitoring has been used to detect peripheral nerve conduction abnormalities indicating peripheral nerve stress under general anesthesia and to guide modification of the upper extremity position to prevent PPNI. POVL usually results in permanent visual loss. Most cases are associated with prolonged spine procedures in the prone position under general anesthesia. The most common causes of POVL after spine surgery are ischemic optic neuropathy and central retinal artery occlusion. Posterior ischemic optic neuropathy is the most common cause of POVL after spine surgery. It is important for spine surgeons to be aware of POVL and to participate in safe, collaborative perioperative care of spine patients. Proper education of perioperative staff, combined with clear communication and collaboration while positioning patients in the operating room is the best and safest approach. The prevention of uncommon complications of spine surgery depends primarily on identifying high-risk patients, proper positioning and optimal intraoperative management of physiological parameters. Modification of risk factors extrinsic to the patient may help reduce the incidence of PPNI and POVL. PMID:25232519

Automated quasi-3D spine curvature quantification and classification

NASA Astrophysics Data System (ADS)

Khilari, Rupal; Puchin, Juris; Okada, Kazunori

2018-02-01

Scoliosis is a highly prevalent spine deformity that has traditionally been diagnosed through measurement of the Cobb angle on radiographs. More recent technology such as the commercial EOS imaging system, although more accurate, also require manual intervention for selecting the extremes of the vertebrae forming the Cobb angle. This results in a high degree of inter and intra observer error in determining the extent of spine deformity. Our primary focus is to eliminate the need for manual intervention by robustly quantifying the curvature of the spine in three dimensions, making it consistent across multiple observers. Given the vertebrae centroids, the proposed Vertebrae Sequence Angle (VSA) estimation and segmentation algorithm finds the largest angle between consecutive pairs of centroids within multiple inflection points on the curve. To exploit existing clinical diagnostic standards, the algorithm uses a quasi-3-dimensional approach considering the curvature in the coronal and sagittal projection planes of the spine. Experiments were performed with manuallyannotated ground-truth classification of publicly available, centroid-annotated CT spine datasets. This was compared with the results obtained from manual Cobb and Centroid angle estimation methods. Using the VSA, we then automatically classify the occurrence and the severity of spine curvature based on Lenke's classification for idiopathic scoliosis. We observe that the results appear promising with a scoliotic angle lying within +/- 9° of the Cobb and Centroid angle, and vertebrae positions differing by at the most one position. Our system also resulted in perfect classification of scoliotic from healthy spines with our dataset with six cases.

Ecotoxicity of Mine Tailings: Unrehabilitated Versus Rehabilitated.

PubMed

Maboeta, M S; Oladipo, O G; Botha, S M

2018-05-01

Earthworms are bioindicators of soil pollution. The ecotoxicity of tailings from selected gold mines in South Africa was investigated utilizing Eisenia andrei bioassays and biomarkers. Samples were obtained from unrehabilitated, rehabilitated and naturally vegetated sites. Biomass, neutral red retention time (NRRT), survival and reproduction were assessed using standardized protocols. Earthworm biomass, NRRT and reproductive success in rehabilitated tailings (comparable to naturally vegetated site) were significantly higher (p < 0.05) than in unrehabilitated tailings. In addition, significantly lower (p < 0.05) body tissue concentrations of As, Cd, Co, Cu and Ni contents were found in the rehabilitated tailings compared to the unrehabilitated. Further, significantly lower (p < 0.05) soil Mn and Zn concentrations were obtained in unrehabilitated tailings than the rehabilitated and naturally vegetated sites. Overall, reduced ecotoxicity effects were confirmed in rehabilitated compared to unrehabilitated tailings. This suggests that rehabilitation as a post-mining restorative strategy has strong positive influence on mine tailings.

Glucocorticoids are critical regulators of dendritic spine development and plasticity in vivo

PubMed Central

Liston, Conor; Gan, Wen-Biao

2011-01-01

Glucocorticoids are a family of hormones that coordinate diverse physiological processes in responding to stress. Prolonged glucocorticoid exposure over weeks has been linked to dendritic atrophy and spine loss in fixed tissue studies of adult brains, but it is unclear how glucocorticoids may affect the dynamic processes of dendritic spine formation and elimination in vivo. Furthermore, relatively few studies have examined the effects of stress and glucocorticoids on spines during the postnatal and adolescent period, which is characterized by rapid synaptogenesis followed by protracted synaptic pruning. To determine whether and to what extent glucocorticoids regulate dendritic spine development and plasticity, we used transcranial two-photon microscopy to track the formation and elimination of dendritic spines in vivo after treatment with glucocorticoids in developing and adult mice. Corticosterone, the principal murine glucocorticoid, had potent dose-dependent effects on dendritic spine dynamics, increasing spine turnover within several hours in the developing barrel cortex. The adult barrel cortex exhibited diminished baseline spine turnover rates, but these rates were also enhanced by corticosterone. Similar changes occurred in multiple cortical areas, suggesting a generalized effect. However, reducing endogenous glucocorticoid activity by dexamethasone suppression or corticosteroid receptor antagonists caused a substantial reduction in spine turnover rates, and the former was reversed by corticosterone replacement. Notably, we found that chronic glucocorticoid excess led to an abnormal loss of stable spines that were established early in life. Together, these findings establish a critical role for glucocorticoids in the development and maintenance of dendritic spines in the living cortex. PMID:21911374

Assessing Risks of Mine Tailing Dam Failures

NASA Astrophysics Data System (ADS)

Concha Larrauri, P.; Lall, U.

2017-12-01

The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

Controversies in "clearing" trauma to the cervical spine.

PubMed

Tins, Bernhard; Cassar-Pullicino, Victor

2007-04-01

Clearance of the traumatic cervical spine is a subject affecting most healthcare professionals dealing with trauma patients. There is a host of often contradictory literature making it hard for an interested reader to come to their own informed opinion based on the current evidence. This review aims to outline the relevant literature for the clearance of the traumatic cervical spine with the particular aim of highlighting the contradictions, controversies and unanswered questions still besetting this important subject. A brief, subjective opinion for a combined clinical and imaging protocol for clearance of the traumatic cervical spine is given.

Telangiectatic osteosarcoma of the spine: a case report.

PubMed

Amritanand, R; Venkatesh, K; Cherian, R; Shah, A; Sundararaj, G D

2008-09-01

Telangiectatic osteosarcoma (TOS) of the spine is rare accounting for only 0.08% of all primary osteosarcomas. Though a well described radio-pathological entity it is not often thought of as a cause of paraplegia. We describe the clinical, radiological and pathological features and discuss the treatment options of telangiectatic osteosarcoma of the dorsal spine presenting in a young man. The diagnostic pitfalls are discussed emphasising the fact that the diagnosis of TOS of the spine requires not only a multi modal approach of appropriate radiological and pathological tests but also an awareness of this condition.

Telangiectatic osteosarcoma of the spine: a case report

PubMed Central

Venkatesh, K.; Cherian, R.; Shah, A.; Sundararaj, G. D.

2008-01-01

Telangiectatic osteosarcoma (TOS) of the spine is rare accounting for only 0.08% of all primary osteosarcomas. Though a well described radio-pathological entity it is not often thought of as a cause of paraplegia. We describe the clinical, radiological and pathological features and discuss the treatment options of telangiectatic osteosarcoma of the dorsal spine presenting in a young man. The diagnostic pitfalls are discussed emphasising the fact that the diagnosis of TOS of the spine requires not only a multi modal approach of appropriate radiological and pathological tests but also an awareness of this condition. PMID:18421481

Active Tails Enhance Arboreal Acrobatics in Geckos

DTIC Science & Technology

2008-03-18

the secret to the gecko s arboreal acrobatics includes an active tail. We examine the tail s role during rapid climbing, aerial descent, and gliding. We show that a gecko s tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle s kickstand. Should a gecko fall with its back to the

Input transformation by dendritic spines of pyramidal neurons

PubMed Central

Araya, Roberto

2014-01-01

In the mammalian brain, most inputs received by a neuron are formed on the dendritic tree. In the neocortex, the dendrites of pyramidal neurons are covered by thousands of tiny protrusions known as dendritic spines, which are the major recipient sites for excitatory synaptic information in the brain. Their peculiar morphology, with a small head connected to the dendritic shaft by a slender neck, has inspired decades of theoretical and more recently experimental work in an attempt to understand how excitatory synaptic inputs are processed, stored and integrated in pyramidal neurons. Advances in electrophysiological, optical and genetic tools are now enabling us to unravel the biophysical and molecular mechanisms controlling spine function in health and disease. Here I highlight relevant findings, challenges and hypotheses on spine function, with an emphasis on the electrical properties of spines and on how these affect the storage and integration of excitatory synaptic inputs in pyramidal neurons. In an attempt to make sense of the published data, I propose that the raison d'etre for dendritic spines lies in their ability to undergo activity-dependent structural and molecular changes that can modify synaptic strength, and hence alter the gain of the linearly integrated sub-threshold depolarizations in pyramidal neuron dendrites before the generation of a dendritic spike. PMID:25520626

A cis-prenyltransferase from Methanosarcina acetivorans catalyzes both head-to-tail and nonhead-to-tail prenyl condensation.

PubMed

Ogawa, Takuya; Emi, Koh-Ichi; Koga, Kazushi; Yoshimura, Tohru; Hemmi, Hisashi

2016-06-01

Cis-prenyltransferase usually consecutively catalyzes the head-to-tail condensation reactions of isopentenyl diphosphate to allylic prenyl diphosphate in the production of (E,Z-mixed) polyprenyl diphosphate, which is the precursor of glycosyl carrier lipids. Some recently discovered homologs of the enzyme, however, catalyze the nonhead-to-tail condensation reactions between allylic prenyl diphosphates. In this study, we characterize a cis-prenyltransferase homolog from a methanogenic archaeon, Methanosarcina acetivorans, to obtain information on the biosynthesis of the glycosyl carrier lipids within it. This enzyme catalyzes both head-to-tail and nonhead-to-tail condensation reactions. The kinetic analysis shows that the main reaction of the enzyme is consecutive head-to-tail prenyl condensation reactions yielding polyprenyl diphosphates, while the chain lengths of the major products seem shorter than expected for the precursor of glycosyl carrier lipids. On the other hand, a subsidiary reaction of the enzyme, i.e., nonhead-to-tail condensation between dimethylallyl diphosphate and farnesyl diphosphate, gives a novel diterpenoid compound, geranyllavandulyl diphosphate. © 2016 Federation of European Biochemical Societies.

[Application of Finite Element Method in Thoracolumbar Spine Traumatology].

PubMed

Zhang, Min; Qiu, Yong-gui; Shao, Yu; Gu, Xiao-feng; Zeng, Ming-wei

2015-04-01

The finite element method (FEM) is a mathematical technique using modern computer technology for stress analysis, and has been gradually used in simulating human body structures in the biomechanical field, especially more widely used in the research of thoracolumbar spine traumatology. This paper reviews the establishment of the thoracolumbar spine FEM, the verification of the FEM, and the thoracolumbar spine FEM research status in different fields, and discusses its prospects and values in forensic thoracolumbar traumatology.

Recycling and utilisation of industrial solid waste: an explorative study on gold deposit tailings of ductile shear zone type in China.

PubMed

Liu, Rui; Huang, Fei; Du, Runxiang; Zhao, Chunming; Li, Yongli; Yu, Haoran

2015-06-01

Tailings are solid waste arising from mineral processing. This type of waste can cause severe damage to the environment during stockpiling as a result of the leaching of something harmful into the ecosystem. Gold deposit of ductile shear zone type is an important type of gold deposit, and the recycling of its tailings has been challenging researchers for a long time. In this article, the characteristics of this type of tailings were systematically studied by using modern technical means. Considering the characteristics of the tailings, clay was selected to make up for the shortcomings of the tailings and improve their performance. Water and raw materials were mixed to produce green bodies, which are subsequently sintered into ceramic bodies at 980 °C~1020 °C (sintering temperature). The results showed that some new kinds of mineral phases, such as mullite, anorthite and orthoclase, appear in ceramic bodies. Furthermore, the ceramic bodies have a surface hardness of 5 to 6 (Mohs scale), and their water absorption and modulus of rupture can meet some technical requirements of ceramic materials described in ISO 13006-2012 and GB 5001-1985. These gold mine tailings can be made into ceramic tiles, domestic ceramic bodies, and other kinds of ceramic bodies for commercial and industrial purposes after further improvements. © The Author(s) 2015.

Non-Ionotropic NMDA Receptor Signaling Drives Activity-Induced Dendritic Spine Shrinkage.

PubMed

Stein, Ivar S; Gray, John A; Zito, Karen

2015-09-02

The elimination of dendritic spine synapses is a critical step in the refinement of neuronal circuits during development of the cerebral cortex. Several studies have shown that activity-induced shrinkage and retraction of dendritic spines depend on activation of the NMDA-type glutamate receptor (NMDAR), which leads to influx of extracellular calcium ions and activation of calcium-dependent phosphatases that modify regulators of the spine cytoskeleton, suggesting that influx of extracellular calcium ions drives spine shrinkage. Intriguingly, a recent report revealed a novel non-ionotropic function of the NMDAR in the regulation of synaptic strength, which relies on glutamate binding but is independent of ion flux through the receptor (Nabavi et al., 2013). Here, we tested whether non-ionotropic NMDAR signaling could also play a role in driving structural plasticity of dendritic spines. Using two-photon glutamate uncaging and time-lapse imaging of rat hippocampal CA1 neurons, we show that low-frequency glutamatergic stimulation results in shrinkage of dendritic spines even in the presence of the NMDAR d-serine/glycine binding site antagonist 7-chlorokynurenic acid (7CK), which fully blocks NMDAR-mediated currents and Ca(2+) transients. Notably, application of 7CK or MK-801 also converts spine enlargement resulting from a high-frequency uncaging stimulus into spine shrinkage, demonstrating that strong Ca(2+) influx through the NMDAR normally overcomes a non-ionotropic shrinkage signal to drive spine growth. Our results support a model in which NMDAR signaling, independent of ion flux, drives structural shrinkage at spiny synapses. Dendritic spine elimination is vital for the refinement of neural circuits during development and has been linked to improvements in behavioral performance in the adult. Spine shrinkage and elimination have been widely accepted to depend on Ca(2+) influx through NMDA-type glutamate receptors (NMDARs) in conjunction with long-term depression

Readability of spine-related patient education materials from subspecialty organization and spine practitioner websites.

PubMed

Vives, Michael; Young, Lyle; Sabharwal, Sanjeev

2009-12-01

Analysis of spine-related websites available to the general public. To assess the readability of spine-related patient educational materials available on professional society and individual surgeon or practice based websites. The Internet has become a valuable source of patient education material. A significant percentage of patients, however, find this Internet based information confusing. Healthcare experts recommend that the readability of patient education material be less than the sixth grade level. The Flesch-Kincaid grade level is the most widely used method to evaluate the readability score of textual material, with lower scores suggesting easier readability. We conducted an Internet search of all patient education documents on the North American Spine Society (NASS), American Association of Neurological Surgeons (AANS), the American Academy of Orthopaedic Surgeons (AAOS), and a sample of 10 individual surgeon or practice based websites. The Flesch-Kincaid grade level of each article was calculated using widely available Microsoft Office Word software. The mean grade level of articles on the various professional society and individual/practice based websites were compared. A total of 121 articles from the various websites were available and analyzed. All 4 categories of websites had mean Flesch-Kincaid grade levels greater than 10. Only 3 articles (2.5%) were found to be at or below the sixth grade level, the recommended readability level for adult patients in the United States. There were no significant differences among the mean Flesch-Kincaid grade levels from the AAOS, NASS, AANS, and practice-based web-sites (P = 0.065, ANOVA). Our findings suggest that most of the Spine-related patient education materials on professional society and practice-based websites have readability scores that may be too high, making comprehension difficult for a substantial portion of the United States adult population.

Are red-tailed hawks and great horned owls diurnal-nocturnal dietary counterparts?

USGS Publications Warehouse

Marti, C.D.; Kochert, Michael N.

1995-01-01

Red-tailed Hawks (Buteo jamaicensis) and Great Homed Owls (Bubo virginianus)are common in North America where they occupy a wide range of habitats, often sympatrically. The two species are similar in size and have been portrayed as ecological counterparts, eating the same prey by day and night. We tested the trophic similarity of the two species by comparing published dietary data from across the United States. Both species ate primarily mammals and birds, and mean proportions of those two prey types did not differ significantly between diets of the two raptors. Red-tailed Hawks ate significantly more reptiles, and Great Homed Owls significantly more invertebrates. Dietary diversity was not significantly different at the level of prey taxonomic class, and diet overlap between the two species averaged 91%. At the prey species level, dietary overlap averaged only 50%, and at that level Red-tailed Hawk dietary diversity was significantly greater than that of Great Horned Owls. Mean prey mass of Red-tailed Hawks was significantly greater than that of Great Homed Owls. Populations of the two species in the western United States differed trophically more than did eastern populations. We conclude that, although the two species are generalist predators, they take largely different prey species in the same localities resulting in distinctive trophic characteristics.

North American Spine Society

MedlinePlus

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Rheumatic diseases of the spine: imaging diagnosis.

PubMed

Narváez, J A; Hernández-Gañán, J; Isern, J; Sánchez-Fernández, J J

2016-04-01

Spinal involvement is common both in the spondyloarthritides and in rheumatoid arthritis, in which the cervical segment is selectively affected. Rheumatoid involvement of the cervical spine has characteristic radiologic manifestations, fundamentally different patterns of atlantoaxial instability. Magnetic resonance imaging (MRI) is the technique of choice for evaluating the possible repercussions of atlantoaxial instability on the spinal cord and/or nerve roots in patients with rheumatoid arthritis as well as for evaluating parameters indicative of active inflammation, such as bone edema and synovitis. Axial involvement is characteristic in the spondyloarthritides and has distinctive manifestations on plain-film X-rays, which reflect destructive and reparative phenomena. The use of MRI has changed the conception of spondyloarthritis because it is able to directly detect the inflammatory changes that form part of the disease, making it possible to establish the diagnosis early in the disease process, when plain-film X-ray findings are normal (non-radiographic axial spondyloarthritis), to assess the prognosis of the disease, and to contribute to treatment planning. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Microscope sterility during spine surgery.

PubMed

Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

2012-04-01

Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

Structural and functional plasticity of dendritic spines – root or result of behavior?

PubMed Central

Gipson, Cassandra D.; Olive, M. Foster

2016-01-01

Dendritic spines are multifunctional integrative units of the nervous system and are highly diverse and dynamic in nature. Both internal and external stimuli influence dendritic spine density and morphology on the order of minutes. It is clear that the structural plasticity of dendritic spines is related to changes in synaptic efficacy, learning and memory, and other cognitive processes. However, it is currently unclear whether structural changes in dendritic spines are primary instigators of changes in specific behaviors, a consequence of behavioral changes, or both. In this review, we first review the basic structure and function of dendritic spines in the brain, as well as laboratory methods to characterize and quantify morphological changes in dendritic spines. We then discuss the existing literature on the temporal and functional relationship between changes in dendritic spines in specific brain regions and changes in specific behaviors mediated by those regions. Although technological advancements have allowed us to better understand the functional relevance of structural changes in dendritic spines that are influenced by environmental stimuli, the role of spine dynamics as an underlying driver or consequence of behavior still remains elusive. We conclude that while it is likely that structural changes in dendritic spines are both instigators and results of behavioral changes, improved research tools and methods are needed to experimentally and directly manipulate spine dynamics in order to more empirically delineate the relationship between spine structure and behavior. PMID:27561549

Clearing the Cervical Spine in a War Zone: What Other Injuries Matter?

DTIC Science & Technology

2015-07-01

Defense Trauma Registry January 2008 to August 2013, identifying blunt trauma patients with cervical spine injury and Glasgow Coma Score > 14...negative clinical examination of the cervical spine . Coexisting injuries identified in patients with negative physical examination included...distracting injuries were present, the physical examination was accurate in all patients. 15. SUBJECT TERMS Cervical spine clearance; cervical spine

Occupant and crash characteristics for case occupants with cervical spine injuries sustained in motor vehicle collisions.

PubMed

Stein, Deborah M; Kufera, Joseph A; Ho, Shiu M; Ryb, Gabriel E; Dischinger, Patricia C; O'Connor, James V; Scalea, Thomas M

2011-02-01

Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database. Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System's Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations. CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR]=1.73, 95% confidence interval [CI]=1.32-2.27) or the use of neither restraint system (OR=1.45, 95% CI=1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15

The Role of Multimodal Analgesia in Spine Surgery.

PubMed

Kurd, Mark F; Kreitz, Tyler; Schroeder, Gregory; Vaccaro, Alexander R

2017-04-01

Optimal postoperative pain control allows for faster recovery, reduced complications, and improved patient satisfaction. Historically, pain management after spine surgery relied heavily on opioid medications. Multimodal regimens were developed to reduce opioid consumption and associated adverse effects. Multimodal approaches used in orthopaedic surgery of the lower extremity, especially joint arthroplasty, have been well described and studies have shown reduced opioid consumption, improved pain and function, and decreased length of stay. A growing body of evidence supports multimodal analgesia in spine surgery. Methods include the use of preemptive analgesia, NSAIDs, the neuromodulatory agents gabapentin and pregabalin, acetaminophen, and extended-action local anesthesia. The development of a standard approach to multimodal analgesia in spine surgery requires extensive assessment of the literature. Because a substantial number of spine surgeries are performed annually, a standardized approach to multimodal analgesia may provide considerable benefits, particularly in the context of the increased emphasis on accountability within the healthcare system.

Patient characteristics of smokers undergoing lumbar spine surgery: an analysis from the Quality Outcomes Database.

PubMed

Asher, Anthony L; Devin, Clinton J; McCutcheon, Brandon; Chotai, Silky; Archer, Kristin R; Nian, Hui; Harrell, Frank E; McGirt, Matthew; Mummaneni, Praveen V; Shaffrey, Christopher I; Foley, Kevin; Glassman, Steven D; Bydon, Mohamad

2017-12-01

OBJECTIVE In this analysis the authors compare the characteristics of smokers to nonsmokers using demographic, socioeconomic, and comorbidity variables. They also investigate which of these characteristics are most strongly associated with smoking status. Finally, the authors investigate whether the association between known patient risk factors and disability outcome is differentially modified by patient smoking status for those who have undergone surgery for lumbar degeneration. METHODS A total of 7547 patients undergoing degenerative lumbar surgery were entered into a prospective multicenter registry (Quality Outcomes Database [QOD]). A retrospective analysis of the prospectively collected data was conducted. Patients were dichotomized as smokers (current smokers) and nonsmokers. Multivariable logistic regression analysis fitted for patient smoking status and subsequent measurement of variable importance was performed to identify the strongest patient characteristics associated with smoking status. Multivariable linear regression models fitted for 12-month Oswestry Disability Index (ODI) scores in subsets of smokers and nonsmokers was performed to investigate whether differential effects of risk factors by smoking status might be present. RESULTS In total, 18% (n = 1365) of patients were smokers and 82% (n = 6182) were nonsmokers. In a multivariable logistic regression analysis, the factors significantly associated with patients' smoking status were sex (p < 0.0001), age (p < 0.0001), body mass index (p < 0.0001), educational status (p < 0.0001), insurance status (p < 0.001), and employment/occupation (p = 0.0024). Patients with diabetes had lowers odds of being a smoker (p = 0.0008), while patients with coronary artery disease had greater odds of being a smoker (p = 0.044). Patients' propensity for smoking was also significantly associated with higher American Society of Anesthesiologists (ASA) class (p < 0.0001), anterior-alone surgical approach (p = 0

Cervical spine injuries from diving accident: a 10-year retrospective descriptive study on 64 patients.

PubMed

Chan-Seng, E; Perrin, F E; Segnarbieux, F; Lonjon, N

2013-09-01

Ninety percent of the lesions resulting from diving injuries affect the cervical spine and are potentially associated with spinal cord injuries. The objective is to determine the most frequent lesion mechanisms. Evaluate the therapeutic alternatives and the biomechanical evolution (kyphotic deformation) of diving-induced cervical spine injuries. Define epidemiological characteristics of diving injuries. A retrospective analysis over a period of 10 years was undertaken for patients admitted to the Department of Neurosurgery of Montpellier, France, with cervical spinal injuries due to a diving accident. Patients were re-evaluated and clinical and radiological evaluation follow-ups were done. This study included 64 patients. Cervical spine injuries resulting from diving predominantly affect young male subjects. They represent 9.5% of all the cervical spine injuries. In 22% of cases, patients presented severe neurological troubles (ASIA A, B, C) at the time of admission. A surgical treatment was done in 85% of cases, mostly using an anterior cervical approach. This is a retrospective study (type IV) with some limitations. The incidence of diving injuries in our region is one of the highest as compared to reports in the literature. Despite an increase of our surgical indications, 55% of these cases end up with a residual kyphotic deformation but there is no relationship between the severity of late vertebral deformity and high Neck Pain and Disability Scale (NPDS) scores. Level IV, retrospective study. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Flexible growing rods: a pilot study to determine if polymer rod constructs may provide stability to skeletally immature spines

PubMed Central

2015-01-01

Background Surgical treatments for early onset scoliosis (EOS), including growing rod constructs, involve many complications. Some are due to biomechanical factors. A construct that is more flexible than current instrumentation systems may reduce complications. The purpose of this preliminary study was to determine spine range of motion (ROM) after implantation of simulated growing rod constructs with a range of clinically relevant structural properties. The hypothesis was that ROM of spines instrumented with polyetheretherketone (PEEK) rods would be greater than metal rods and lower than noninstrumented controls. Further, adjacent segment motion was expected to be lower with polymer rods compared to conventional systems. Methods Biomechanical tests were conducted on 6 skeletally immature porcine thoracic spines (domestic swine, 35-40 kg). Spines were harvested after death from swine that had been utilized for other studies (IACUC approved) which had not involved the spine. Paired pedicle screws were used as anchors at proximal and distal levels. Specimens were tested under the following conditions: control, then dual rods of PEEK (6.25 mm), titanium (4 mm), and CoCr (5 mm) alloy. Lateral bending (LB) and flexion-extension (FE) moments of ±5 Nm were applied. Vertebral rotations were measured using video. Differences were determined by two-tailed t-tests and Bonferroni correction with four primary comparisons: PEEK vs control and PEEK vs CoCr, in LB and FE (α=0.05/4). Results In LB, ROM of specimens with PEEK rods was lower than control at each instrumented level. ROM was greater for PEEK rods than both Ti and CoCr at every instrumented level. Mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for Ti and CoCr. In FE, mean ROM at proximal and distal noninstrumented levels was lower for PEEK than for metal. Combining treated levels, in LB, ROM for PEEK rods was 35% of control (p<0.0001) and 270% of CoCr rods (p<0.01). In FE, ROM with PEEK

In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.).

PubMed

Le Guernic, Antoine; Sanchez, Wilfried; Bado-Nilles, Anne; Palluel, Olivier; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Delahaut, Laurence; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-08-01

Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.

Management of thoracolumbar spine trauma: An overview

PubMed Central

Rajasekaran, S; Kanna, Rishi Mugesh; Shetty, Ajoy Prasad

2015-01-01

Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Controversies exist regarding the appropriate radiological investigations, the indications for surgical management and the timing, approach and type of surgery. This review provides an overview of the epidemiology, biomechanical principles, radiological and clinical evaluation, classification and management principles. Literature review of all relevant articles published in PubMed covering thoracolumbar spine fractures with or without neurologic deficit was performed. The search terms used were thoracolumbar, thoracic, lumbar, fracture, trauma and management. All relevant articles and abstracts covering thoracolumbar spine fractures with and without neurologic deficit were reviewed. Biomechanically the thoracolumbar spine is predisposed to a higher incidence of spinal injuries. Computed tomography provides adequate bony detail for assessing spinal stability while magnetic resonance imaging shows injuries to soft tissues (posterior ligamentous complex [PLC]) and neurological structures. Different classification systems exist and the most recent is the AO spine knowledge forum classification of thoracolumbar trauma. Treatment includes both nonoperative and operative methods and selected based on the degree of bony injury, neurological involvement, presence of associated injuries and the integrity of the PLC. Significant advances in imaging have helped in the better understanding of thoracolumbar fractures, including information on canal morphology and injury to soft tissue structures. The ideal classification that is simple, comprehensive and guides management is still elusive. Involvement of three columns, progressive neurological deficit, significant kyphosis and canal compromise with neurological deficit are accepted indications for surgical stabilization through anterior, posterior or combined approaches. PMID:25593358

Paediatric cervical spine injures. Nineteen years experience of a single centre.

PubMed

Ribeiro da Silva, Manuel; Linhares, Daniela; Cacho Rodrigues, Pedro; Monteiro, Eurico Lisboa; Santos Carvalho, Manuel; Negrão, Pedro; Pinto, Rui Peixoto; Neves, Nuno

2016-06-01

This observational study aims to describe pediatric C-spine injuries from a level 1 trauma centre through a period of 19 years. Clinical records of pediatric trauma patients admitted to a level 1 trauma centre between 1991 and 2009 were analyzed. Patients were stratified by age into groups A (8 or less) and B (9 to 16), and in lower (C0-C2) and upper (C3-C7) spine injuries. Several variables were studied. Seventy-five cases of C-spine injuries (nine SCIWORA) were identified. Group A included 23 patients and group B 52. In group A, skeletal injuries at the upper C-spine were more common than injuries at the lower C-spine, whereas in group B, injuries of the lower C-spine were more frequent (p = 0.035). Motor vehicle accidents were the main cause of injury (44 %); 25.3 % of patients were surgically treated. Thirty-nine patients presented neurologic deficits, 16 of which improved. The overall mortality rate was 18.7 % and significantly higher in patients with neurological damages (p < 0.001) CONCLUSIONS: This study revealed a low incidence of cervical spine injuries in the paediatric population. As in previous reports younger children mainly sustained injuries at the upper C-spine, higher incidence of spinal injuries, and higher risk of death than older children.

Ecological aspects of microorganisms inhabiting uranium mill tailings

USGS Publications Warehouse

Miller, C.L.; Landa, E.R.; Updegraff, D.M.

1987-01-01

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.

Dose conformation to the spine during palliative treatments using dynamic wedges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ormsby, Matthew A., E-mail: Matthew.Ormsby@usoncology.com; Herndon, R. Craig; Kaczor, Joseph G.

2013-07-01

Radiation therapy is commonly used to alleviate pain associated with metastatic disease of the spine. Often, isodose lines are manipulated using dynamic or physical wedges to encompass the section of spine needing treatment while minimizing dose to normal tissue. We will compare 2 methods used to treat the entire thoracic spine. The first method treats the thoracic spine with a single, nonwedged posterior-anterior (PA) field. Dose is prescribed to include the entire spine. Isodose lines tightly conform to the top and bottom vertebrae, but vertebrae between these 2 received more than enough coverage. The second method uses a combination ofmore » wedges to create an isodose line that mimics the curvature of the thoracic spine. This “C”-shaped curvature is created by overlapping 2 fields with opposing dynamic wedges. Machine constraints limit the treatment length and therefore 2 isocenters are used. Each of the 2 PA fields contributes a portion of the total daily dose. This technique creates a “C”-shaped isodose line that tightly conforms to the thoracic spine, minimizing normal tissue dose. Spinal cord maximum dose is reduced, as well as mean dose to the liver, esophagus, and heart.« less

Therapeutic strategy and outcome of spine tumors in pregnancy: a report of 21 cases and literature review.

PubMed

Meng, Tong; Yin, Huabin; Li, Zhenxi; Li, Bo; Zhou, Wang; Wang, Jing; Zhou, Lei; Song, Dianwen; Xiao, Jianru

2015-02-01

A retrospective study was performed. To illustrate the characteristics of spine tumors during pregnancy and obtain better insight into therapeutic strategies of such tumors by analyzing 21 cases treated in Changzheng Hospital and reviewing previous reports in the literature. The concurrence of spine tumors and pregnancy is relatively rare. There are controversies over the treatment options for this disease, which increase the difficulty of the clinical treatment. Between 2002 and 2013, 21 pregnant patients were identified with spine tumors. Clinical data including symptoms, signs, treatment options, and obstetrical and neonatal outcomes were recorded and preserved. Clinical data and treatment efficacy were analyzed via medical record review. The median age of the 21 patients was 28.87 years (interquartile range, 6.00 yr). Tumor types in this series were giant cell tumor (5 cases), hemangioma (5 cases), schwannoma (4 cases), eosinophilic granuloma (2 cases), neurofibroma (1 case), multiple myeloma (1 case), and with metastatic tumor (3 cases). Two patients underwent spine surgery during pregnancy and 8 patients accepted tumor resection immediately after delivery. Pregnancy termination occurred in 5 patients, whereas the rest of the patients smoothly gave birth to healthy babies including 3 premature infants. Two patients died and 2 patients experienced local recurrence during follow-up. With close observation, it was found that most of pregnant patients with benign spine tumors could postpone surgery after delivery. Surgical treatment should be adopted during pregnancy when patients are with highly malignant tumor or experience a sharp deterioration and the guard of it is safer than radiotherapy and chemotherapy during pregnancy. 4.

Cervical spine injuries in rugby players.

PubMed Central

Sovio, O. M.; Van Peteghem, P. K.; Schweigel, J. F.

1984-01-01

Nine patients with serious cervical spine injuries that occurred while they were playing rugby were seen in a British Columbia acute spinal cord injury unit during the period 1975-82. All the injuries had occurred during the "scrum" or the "tackle". Two of the patients were rendered permanently quadriplegic, and one patient died. There is a need for a central registry that would record all cervical spine injuries in rugby players as well as for changes in the rules of the game. Images Fig. 1 PMID:6697282

Racial Disparities in 30-Day Readmission Rates After Elective Spine Surgery: A Single Institutional Experience.

PubMed

Adogwa, Owoicho; Elsamadicy, Aladine A; Mehta, Ankit I; Cheng, Joseph; Bagley, Carlos A; Karikari, Isaac O

2016-11-01

Retrospective cohort review. The aim of this study is to investigate whether patient race is an independent predictor of unplanned 30-day hospital readmission after elective spine surgery. Racial disparities are known to exist for many aspects of surgical care. However, it is unknown if disparities exist in 30-day readmissions after elective spine surgery, an area that is becoming a prime focus for clinical leaders and policymakers. Records of 600 patients undergoing elective spine surgery at a major academic medical center were reviewed. We identified all unplanned readmissions within 30 days of discharge. Unplanned readmissions were defined to have occurred as a result of either a surgical or a nonsurgical complication. Patient's records were reviewed to determine the cause of readmission and the length of hospital stay. The main outcome measure was risk-adjusted odds of all-cause 30-day readmission. We used multivariate logistic regression to determine if Black patients had an increased likelihood of 30-day readmission compared with White patients. Baseline characteristics were similar between both groups. Black patients had higher readmission rates than White patients (10.56% vs. 7.86%, P = 0.04). In a univariate analysis, race, body mass index, sex, patient age, smoking, diabetes, and fusion levels were associated with increased 30-day readmission rates. However, in a multivariate logistic regression model, race was an independent predictor of 30-day readmission after elective spine surgery. In addition, no significant differences in baseline, 1-year and 2-year patient reported outcomes measures were observed between both groups. This study suggests that Black patients are more likely to be readmitted within 30-days of discharge after elective spine surgery. Efforts at reducing disparities should focus not only on race-based measures but also effective post discharge care. 3.

Targeted intracellular voltage recordings from dendritic spines using quantum-dot-coated nanopipettes

NASA Astrophysics Data System (ADS)

Jayant, Krishna; Hirtz, Jan J.; Plante, Ilan Jen-La; Tsai, David M.; de Boer, Wieteke D. A. M.; Semonche, Alexa; Peterka, Darcy S.; Owen, Jonathan S.; Sahin, Ozgur; Shepard, Kenneth L.; Yuste, Rafael

2017-05-01

Dendritic spines are the primary site of excitatory synaptic input onto neurons, and are biochemically isolated from the parent dendritic shaft by their thin neck. However, due to the lack of direct electrical recordings from spines, the influence that the neck resistance has on synaptic transmission, and the extent to which spines compartmentalize voltage, specifically excitatory postsynaptic potentials, albeit critical, remains controversial. Here, we use quantum-dot-coated nanopipette electrodes (tip diameters ∼15-30 nm) to establish the first intracellular recordings from targeted spine heads under two-photon visualization. Using simultaneous somato-spine electrical recordings, we find that back propagating action potentials fully invade spines, that excitatory postsynaptic potentials are large in the spine head (mean 26 mV) but are strongly attenuated at the soma (0.5-1 mV) and that the estimated neck resistance (mean 420 MΩ) is large enough to generate significant voltage compartmentalization. Nanopipettes can thus be used to electrically probe biological nanostructures.

Targeted intracellular voltage recordings from dendritic spines using quantum-dot-coated nanopipettes

PubMed Central

Jayant, Krishna; Hirtz, Jan J.; Plante, Ilan Jen-La; Tsai, David M.; De Boer, Wieteke D. A. M.; Semonche, Alexa; Peterka, Darcy S.; Owen, Jonathan S.; Sahin, Ozgur; Shepard, Kenneth L.; Yuste, Rafael

2017-01-01

Dendritic spines are the primary site of excitatory synaptic input onto neurons, and are biochemically isolated from the parent dendritic shaft by their thin neck. However, due to the lack of direct electrical recordings from spines, the influence that the neck resistance has on synaptic transmission, and the extent to which spines compartmentalize voltage, specifically excitatory postsynaptic potentials, albeit critical, remains controversial. Here, we use quantum-dot-coated nanopipette electrodes (tip diameters ~15–30 nm) to establish the first intracellular recordings from targeted spine heads under two-photon visualization. Using simultaneous somato-spine electrical recordings, we find that back propagating action potentials fully invade spines, that excitatory postsynaptic potentials are large in the spine head (mean 26 mV) but are strongly attenuated at the soma (0.5–1 mV) and that the estimated neck resistance (mean 420 MΩ) is large enough to generate significant voltage compartmentalization. Nanopipettes can thus be used to electrically probe biological nanostructures. PMID:27941898

Targeted intracellular voltage recordings from dendritic spines using quantum-dot-coated nanopipettes.

PubMed

Jayant, Krishna; Hirtz, Jan J; Plante, Ilan Jen-La; Tsai, David M; De Boer, Wieteke D A M; Semonche, Alexa; Peterka, Darcy S; Owen, Jonathan S; Sahin, Ozgur; Shepard, Kenneth L; Yuste, Rafael

2017-05-01

Dendritic spines are the primary site of excitatory synaptic input onto neurons, and are biochemically isolated from the parent dendritic shaft by their thin neck. However, due to the lack of direct electrical recordings from spines, the influence that the neck resistance has on synaptic transmission, and the extent to which spines compartmentalize voltage, specifically excitatory postsynaptic potentials, albeit critical, remains controversial. Here, we use quantum-dot-coated nanopipette electrodes (tip diameters ∼15-30 nm) to establish the first intracellular recordings from targeted spine heads under two-photon visualization. Using simultaneous somato-spine electrical recordings, we find that back propagating action potentials fully invade spines, that excitatory postsynaptic potentials are large in the spine head (mean 26 mV) but are strongly attenuated at the soma (0.5-1 mV) and that the estimated neck resistance (mean 420 MΩ) is large enough to generate significant voltage compartmentalization. Nanopipettes can thus be used to electrically probe biological nanostructures.

Complications of Anterior and Posterior Cervical Spine Surgery

PubMed Central

Cheung, Jason Pui Yin

2016-01-01

Cervical spine surgery performed for the correct indications yields good results. However, surgeons need to be mindful of the many possible pitfalls. Complications may occur starting from the anaesthestic procedure and patient positioning to dura exposure and instrumentation. This review examines specific complications related to anterior and posterior cervical spine surgery, discusses their causes and considers methods to prevent or treat them. In general, avoiding complications is best achieved with meticulous preoperative analysis of the pathology, good patient selection for a specific procedure and careful execution of the surgery. Cervical spine surgery is usually effective in treating most pathologies and only a reasonable complication rate exists. PMID:27114784

An Architectonic Study of the Neocortex of the Short-Tailed Opossum (Monodelphis domestica)

PubMed Central

Wong, Peiyan; Kaas, Jon H.

2013-01-01

Short-tailed opossums (Monodelphis domestica) belong to the branch of marsupial mammals that diverged from eutherian mammals approximately 180 million years ago. They are small in size, lack a marsupial pouch, and may have retained more morphological characteristics of early marsupial neocortex than most other marsupials. In the present study, we used several different histochemical and immunochemical procedures to reveal the architectonic characteristics of cortical areas in short-tailed opossums. Subdivisions of cortex were identified in brain sections cut in the coronal, sagittal, horizontal or tangential planes and processed for a calcium-binding protein, parvalbumin (PV), neurofilament protein epitopes recognized by SMI-32, the vesicle glutamate transporter 2 (VGluT2), myelin, cytochrome oxidase (CO), and Nissl substance. These different procedures revealed similar boundaries among areas, suggesting that functionally relevant borders were detected. The results allowed a fuller description and more precise demarcation of previously identified sensory areas, and the delineation of additional subdivisions of cortex. Area 17 (V1) was especially prominent, with a densely populated layer 4, high myelination levels, and dark staining of PV and VGluT2 immunopositive terminations. These architectonic features were present, albeit less pronounced, in somatosensory and auditory cortex. The major findings support the conclusion that short-tailed opossums have fewer cortical areas and their neocortex is less distinctly laminated than most other mammals. PMID:19546531

The X-ray Crystal Structure of the Phage Tail Terminator Protein Reveals the Biologically Relevant Hexameric Rang Structure and Demonstrates a Conserved mechanism of Tail Termination among Divrse Long Tailed Phages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pell, L.; Liu, A; Edmonds, L

The tail terminator protein (TrP) plays an essential role in phage tail assembly by capping the rapidly polymerizing tail once it has reached its requisite length and serving as the interaction surface for phage heads. Here, we present the 2.7-A crystal structure of a hexameric ring of gpU, the TrP of phage ?. Using sequence alignment analysis and site-directed mutagenesis, we have shown that this multimeric structure is biologically relevant and we have delineated its functional surfaces. Comparison of the hexameric crystal structure with the solution structure of gpU that we previously solved using NMR spectroscopy shows large structural changesmore » occurring upon multimerization and suggests a mechanism that allows gpU to remain monomeric at high concentrations on its own, yet polymerize readily upon contact with an assembled tail tube. The gpU hexamer displays several flexible loops that play key roles in head and tail binding, implying a role for disorder-to-order transitions in controlling assembly as has been observed with other ? morphogenetic proteins. Finally, we have found that the hexameric structure of gpU is very similar to the structure of a putative TrP from a contractile phage tail even though it displays no detectable sequence similarity. This finding coupled with further bioinformatic investigations has led us to conclude that the TrPs of non-contractile-tailed phages, such as ?, are evolutionarily related to those of contractile-tailed phages, such as P2 and Mu, and that all long-tailed phages may utilize a conserved mechanism for tail termination.« less

Transmission of force in the lumbosacral spine during backward falls.

PubMed

Van Toen, Carolyn; Sran, Meena M; Robinovitch, Stephen N; Cripton, Peter A

2012-04-20

Mathematical model, combined with and verified using human subject data. (1) To develop and verify a lumped-parameter mathematical model for prediction of spine forces during backward falls; (2) to use this model to evaluate the effect of floor stiffness on spine forces during falls; and (3) to compare predicted impact forces with forces previously measured to fracture the spine. Vertebral fractures are the most common osteoporotic fractures and commonly result from falls from standing height. Compliant flooring reduces the force at the ground during a backward fall from standing; however, the effect on spine forces is unknown. A 6-df model of the body was developed and verified using data from 10 human subjects falling from standing onto 3 types of compliant floors (soft: 59 kN/m, medium: 67 kN/m, and firm: 95 kN/m). The simulated ground forces were compared with those measured experimentally. The model was also used to assess the effect of floor stiffness on spine forces at various intervertebral levels. There was less than 14% difference between model predictions and experimentally measured peak ground reaction forces, when averaged over all floor conditions. When compared with the rigid floor, average peak spine force attenuations of 46%, 43%, and 41% were achieved with the soft, medium, and firm floors, respectively (3.7, 3.9, 4.1 kN vs. 6.9 kN at L4/L5). Spine forces were lower than those at the ground and decreased cranially (4.9, 3.9, 3.7, 3.5 kN at the ground, L5/S1, L4/L5, and L3/L4, respectively, for the soft floor). Lowering the floor stiffness (from 400 to 59 kN/m) can attenuate peak lumbosacral spine forces in a backward fall onto the buttocks from standing by 46% (average peak from 6.9 to 3.7 kN at L4/L5) to values closer to the average tolerance of the spine to fracture (3.4 kN).

Advantages and disadvantages of nonfusion technology in spine surgery.

PubMed

Huang, Russel C; Girardi, Federico P; Lim, Moe R; Cammisa, Frank P

2005-07-01

Nonfusion technology in spine surgery may improve outcomes by reducing surgical morbidity and the incidence of adjacent level degeneration; however, new technologies also introduce new short- and long-term complications. There is currently no evidence that nonfusion implants are superior to fusion in mid- to long-term follow-up. Understanding the potential risks and benefits of nonfusion technology is essential for spine surgeons and their patients. This article reviews the current evidence relating to the potential risks and benefits of nonfusion technology in spine surgery.

Physicochemical Characterization of Aeolian Mine Tailings Dust in the Southwest USA

NASA Astrophysics Data System (ADS)

Betterton, E. A.; Barbaris, B.; Conant, W.; Csavina, J.; Gao, S.; Lund, L.; Rheinheimer, P.; Saez, E.; Wonaschutz, A.

2008-12-01

Census data reveal that the Southwest is the fastest growing region of the USA, while NOAA GFDL coupled- model results suggest that precipitation is expected to decline in the same region over the coming decades. Besides the obvious impact on water resources, the drier conditions will most likely also result in increased atmospheric dust loads that could impact the health of a rapidly increasing population. This year the US EPA began site assessment and remediation at two mine tailings piles in Arizona contaminated with arsenic, lead, chromium and cadmium. The first is located in the twin towns of Hayden and Winkleman, and the second at the Iron King mine near Humbolt. At a concentration of approximately 0.1 microgram per cubic meter, the level of arsenic in PM10 collected at Hayden/Winkelman sometimes exceeds the Arizona ambient hazardous air pollutant standard (HAPS) by several orders of magnitude. Lead, cadmium and chromium are also sometimes orders of magnitude higher than the HAPS. A top priority is to determine the physicochemical speciation of wind-blown dust as a function of particle diameter because this information can a) help with source apportionment of airborne pollutants (e.g., smelter emissions vs. tailings dust), and b) help to assess the potential health impacts of contaminated dust, since deposition efficiency in human lungs is a strong function of particle diameter. We will present the chemical and physical characteristics of mine tailings dust collected with 10-stage multiple orifice uniform deposit impactors (MOUDI) located at Hayden/Winkleman and Iron King. We will also present scanning mobility particle spectrometer (SMPS) data obtained from the same sites. The MOUDI yields particle composition by size fraction (0.056-18 micrometer aerodynamic diameter) while the SMPS yields particle number by size fraction (0.0025 to 1.0 micrometer diameter). Size selective characteristics such as these have never been previously reported for mine tailings

Riding position and lumbar spine angle in recreational cyclists: A pilot study

PubMed Central

SCHULZ, SAMANTHA J.; GORDON, SUSAN J.

2010-01-01

This pilot study investigated the reliability of an inclinometer to assess lumbar spine angle in three different cycling positions, and explored the relationship between lumbar spine angle and riding position, anthropometry, bike measures and low back pain (LBP). Cyclists were recruited from two cycle clubs. Anthropometric variables and bike setup were measured before participants’ bikes were secured in a wind trainer. Cyclists then adopted three positions for riding, upright on the handlebars, on the brake levers and on the drops, according to a random allocation. The angle of the lumbar spine was measured; using an inclinometer, at zero minutes and after cyclists had completed 10 minutes of cycling. Intra-measurer reliability for inclinometer use to measure lumbar spine angle in each position was excellent (ICC=0.97). The angle of the lumbar spine changed significantly over 10 minutes in the brake position (p=0.004). Lumbar spine angle at 10 minutes was significantly different between the brake and drop positions (p=0.018, p<0.05), and between upright and drop positions (p=0.012, p<0.05). Lumbar spine angle was not related to anthropometric measures. The change in lumbar spine angle varied from one degree of extension to 12 degrees of flexion, with increased flexion occurring in 95% of trials. An inclinometer has excellent intra-measurer reliability to measure lumbar spine angle in cycling positions. Future research with a sample of 72 or more participants is required to determine if there is a significant relationship between LBP and lumbar spine angle in different cycling positions. PMID:27182345

Robotics and the spine: a review of current and ongoing applications.

PubMed

Shweikeh, Faris; Amadio, Jordan P; Arnell, Monica; Barnard, Zachary R; Kim, Terrence T; Johnson, J Patrick; Drazin, Doniel

2014-03-01

Robotics in the operating room has shown great use and versatility in multiple surgical fields. Robot-assisted spine surgery has gained significant favor over its relatively short existence, due to its intuitive promise of higher surgical accuracy and better outcomes with fewer complications. Here, the authors analyze the existing literature on this growing technology in the era of minimally invasive spine surgery. In an attempt to provide the most recent, up-to-date review of the current literature on robotic spine surgery, a search of the existing literature was conducted to obtain all relevant studies on robotics as it relates to its application in spine surgery and other interventions. In all, 45 articles were included in the analysis. The authors discuss the current status of this technology and its potential in multiple arenas of spinal interventions, mainly spine surgery and spine biomechanics testing. There are numerous potential advantages and limitations to robotic spine surgery, as suggested in published case reports and in retrospective and prospective studies. Randomized controlled trials are few in number and show conflicting results regarding accuracy. The present limitations may be surmountable with future technological improvements, greater surgeon experience, reduced cost, improved operating room dynamics, and more training of surgical team members. Given the promise of robotics for improvements in spine surgery and spine biomechanics testing, more studies are needed to further explore the applicability of this technology in the spinal operating room. Due to the significant cost of the robotic equipment, studies are needed to substantiate that the increased equipment costs will result in significant benefits that will justify the expense.

78 FR 68906 - Agency Information Collection (Back (Thoracolumbar Spine) Conditions Disability Benefits...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-15

... (Thoracolumbar Spine) Conditions Disability Benefits Questionnaire) Under OMB Review AGENCY: Veterans Benefits... Control No. 2900- NEW (Back (Thoracolumbar Spine) Conditions Disability Benefits Questionnaire)'' in any... Disability Benefits Questionnaire)''. SUPPLEMENTARY INFORMATION: Title: (Back (Thoracolumbar Spine...

A case of tophaceous gout in the lumbar spine: a review of the literature and treatment recommendations.

PubMed

Jegapragasan, Mithulan; Calniquer, Alejandro; Hwang, William D; Nguyen, Quynh T; Child, Zachary

2014-04-01

Study Design Case report. Objective The objective of this study is to report the occurrence of tophaceous gout in the lumbar spine. Methods Using a case report to illustrate the key points of gout in the spine, we provide a brief review of gout in the literature as it relates to its orthopedic and spinal manifestations as well as guidelines for management. Results This case report details the occurrence of a large and clinically significant finding of tophaceous gout in the lumbar spine in a 24-year-old man with a known history of gout and a 3-year history of progressive back pain. Conclusion A high index of suspicion can assist in diagnosis of patients presenting with back pain or neurologic findings with a history of gout. A previous history of gout (especially the presence of tophi), hyperuricemia, and the radiological characteristics presented here should aid the clinician in making the diagnosis of spinal gout. Early diagnosis has the potential to prevent the need for surgical intervention.

Autofusion in the immature spine treated with growing rods.

PubMed

Cahill, Patrick J; Marvil, Sean; Cuddihy, Laury; Schutt, Corey; Idema, Jocelyn; Clements, David H; Antonacci, M Darryl; Asghar, Jahangir; Samdani, Amer F; Betz, Randal R

2010-10-15

Retrospective case review of skeletally immature patients treated with growing rods. Patients received an average of 9.6 years follow-up care. (1) to identify the rate of autofusion in the growing spine with the use of growing rods; (2) to quantify how much correction can be attained with definitive instrumented fusion after long-term treatment with growing rods; and (3) to describe the extent of Smith-Petersen osteotomies required to gain correction of an autofused spine following growing rod treatment. The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While autofusion has been reported, the prevalence and sequelae are not known. Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted and the following data collected: complications, pre- and postoperative Cobb angles at time of initial surgery (growing rod placement), pre- and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1-S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have autofusion at the time of device removal. The rate of autofusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, 7 osteotomies per patient were required at the time of definitive fusion due to autofusion. Although growing rods have efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended autofusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.

Cervical spine dysfunctions in patients with chronic subjective tinnitus.

PubMed

Michiels, Sarah; De Hertogh, Willem; Truijen, Steven; Van de Heyning, Paul

2015-04-01

To assess, characterize, and quantify cervical spine dysfunction in patients with cervicogenic somatic tinnitus (CST) compared to patients suffering from other forms of chronic subjective non-pulsatile tinnitus. Cross-sectional study. Tertiary referral center. Consecutive adult patients suffering from chronic subjective non-pulsatile tinnitus were included. Ménière's disease, middle ear pathology, intracranial pathology, cervical spine surgery, whiplash trauma, temporomandibular dysfunction. Assessment comprises medical history, ENT examination with micro-otoscopy, audiometry, tinnitus assessment, temporomandibular and cervical spine investigation, and brain MRI. Patients were classified into CST and non-CST population. Cervical spine dysfunction was investigated using the Neck Bournemouth Questionnaire (NBQ) and clinical tests of the cervical spine, containing range of motion, pain provocation (adapted Spurling test, AST), and muscle tests (tenderness via trigger points, strength and endurance of deep neck flexors). Between-group analysis was performed. The prevalence of cervical spine dysfunction was described for the total group and for CST and non-CST groups. In total, 87 patients were included, of which 37 (43%) were diagnosed with CST. In comparison with the non-CST group, the CST group demonstrated a significantly higher prevalence of cervical spine dysfunction. In the CST group, 68% had a positive manual rotation test, 47% a positive AST, 49% a positive score on both, and 81% had positive trigger points. In the non-CST group, these percentages were 36, 18, 10, and 50%, respectively. Furthermore, 79% of the CST group had a positive NBQ versus 40% in the non-CST group. Significant differences between the both groups were found for all the aforementioned variables (all p < 0.005). Although a higher prevalence of neck dysfunction was found in the CST group, neck dysfunction is often in non-CST patients.

Opposite effects of fear conditioning and extinction on dendritic spine remodelling.

PubMed

Lai, Cora Sau Wan; Franke, Thomas F; Gan, Wen-Biao

2012-02-19

It is generally believed that fear extinction is a form of new learning that inhibits rather than erases previously acquired fear memories. Although this view has gained much support from behavioural and electrophysiological studies, the hypothesis that extinction causes the partial erasure of fear memories remains viable. Using transcranial two-photon microscopy, we investigated how neural circuits are modified by fear learning and extinction by examining the formation and elimination of postsynaptic dendritic spines of layer-V pyramidal neurons in the mouse frontal association cortex. Here we show that fear conditioning by pairing an auditory cue with a footshock increases the rate of spine elimination. By contrast, fear extinction by repeated presentation of the same auditory cue without a footshock increases the rate of spine formation. The degrees of spine remodelling induced by fear conditioning and extinction strongly correlate with the expression and extinction of conditioned fear responses, respectively. Notably, spine elimination and formation induced by fear conditioning and extinction occur on the same dendritic branches in a cue- and location-specific manner: cue-specific extinction causes formation of dendritic spines within a distance of two micrometres from spines that were eliminated after fear conditioning. Furthermore, reconditioning preferentially induces elimination of dendritic spines that were formed after extinction. Thus, within vastly complex neuronal networks, fear conditioning, extinction and reconditioning lead to opposing changes at the level of individual synapses. These findings also suggest that fear memory traces are partially erased after extinction.

Sagittal alignment of the cervical spine after neck injury.

PubMed

Beltsios, Michail; Savvidou, Olga; Mitsiokapa, Evanthia A; Mavrogenis, Andreas F; Kaspiris, Angelos; Efstathopoulos, Nikolaos; Papagelopoulos, Panayiotis J

2013-07-01

The normal sagittal alignment of the cervical spine is lordotic and is affected by the posture of the head and neck. The question of whether loss of cervical lordosis is the result of muscle spasm after injury or a normal variation, and the clinical significance of such changes in sagittal profile of the cervical spine has been an issue of several studies. The purpose of this paper is to study the incidence of normal cervical lordosis and its changes after neck injury compared to the healthy population. We studied the lateral radiographs of the cervical spine of 60 patients with neck injury compared to 100 patients without a neck injury. Lateral radiographs were obtained in the standing or sitting position, and the curvature of the cervical spine was measured using the angle formed between the inferior end plates of the C2 and C7 vertebrae. In the patients without neck injury, lordotic and straight cervical spine sagittal alignment was observed in 36.5% each, double curvature in 17%, and kyphotic in 10%. In the patients with neck injury, lordotic sagittal alignment was observed in 36%, straight in 34%, double curvature in 26% and kyphotic in 4%. No significant difference between the two groups regarding all types of sagittal alignment of the cervical spine was found (p > 0.100). The alterations in normal cervical lordosis in patients with neck injury must be considered coincidental. These alterations should not be associated with muscle spasm caused by neck pain.

Performance Indicators in Spine Surgery.

PubMed

St-Pierre, Godefroy Hardy; Yang, Michael H; Bourget-Murray, Jonathan; Thomas, Ken C; Hurlbert, Robin John; Matthes, Nikolas

2018-02-15

Systematic review. To elucidate how performance indicators are currently used in spine surgery. The Patient Protection and Affordable Care Act has given significant traction to the idea that healthcare must provide value to the patient through the introduction of hospital value-based purchasing. The key to implementing this new paradigm is to measure this value notably through performance indicators. MEDLINE, CINAHL Plus, EMBASE, and Google Scholar were searched for studies reporting the use of performance indicators specific to spine surgery. We followed the Prisma-P methodology for a systematic review for entries from January 1980 to July 2016. All full text articles were then reviewed to identify any measure of performance published within the article. This measure was then examined as per the three criteria of established standard, exclusion/risk adjustment, and benchmarking to determine if it constituted a performance indicator. The initial search yielded 85 results among which two relevant studies were identified. The extended search gave a total of 865 citations across databases among which 15 new articles were identified. The grey literature search provided five additional reports which in turn led to six additional articles. A total of 27 full text articles and reports were retrieved and reviewed. We were unable to identify performance indicators. The articles presenting a measure of performance were organized based on how many criteria they lacked. We further examined the next steps to be taken to craft the first performance indicator in spine surgery. The science of performance measurement applied to spine surgery is still in its infancy. Current outcome metrics used in clinical settings require refinement to become performance indicators. Current registry work is providing the necessary foundation, but requires benchmarking to truly measure performance. 1.

Collection Efficiency and Ice Accretion Characteristics of Two Full Scale and One 1/4 Scale Business Jet Horizontal Tails

NASA Technical Reports Server (NTRS)

Bidwell, Colin S.; Papadakis, Michael

2005-01-01

Collection efficiency and ice accretion calculations have been made for a series of business jet horizontal tail configurations using a three-dimensional panel code, an adaptive grid code, and the NASA Glenn LEWICE3D grid based ice accretion code. The horizontal tail models included two full scale wing tips and a 25 percent scale model. Flow solutions for the horizontal tails were generated using the PMARC panel code. Grids used in the ice accretion calculations were generated using the adaptive grid code ICEGRID. The LEWICE3D grid based ice accretion program was used to calculate impingement efficiency and ice shapes. Ice shapes typifying rime and mixed icing conditions were generated for a 30 minute hold condition. All calculations were performed on an SGI Octane computer. The results have been compared to experimental flow and impingement data. In general, the calculated flow and collection efficiencies compared well with experiment, and the ice shapes appeared representative of the rime and mixed icing conditions for which they were calculated.

Induction of dendritic spines by β2-containing nicotinic receptors.

PubMed

Lozada, Adrian F; Wang, Xulong; Gounko, Natalia V; Massey, Kerri A; Duan, Jingjing; Liu, Zhaoping; Berg, Darwin K

2012-06-13

Glutamatergic synapses are located mostly on dendritic spines in the adult nervous system. The spines serve as postsynaptic compartments, containing components that mediate and control the synaptic signal. Early in development, when glutamatergic synapses are initially forming, waves of excitatory activity pass through many parts of the nervous system and are driven in part by a class of heteropentameric β2-containing nicotinic acetylcholine receptors (β2*-nAChRs). These β2*-nAChRs are widely distributed and, when activated, can depolarize the membrane and elevate intracellular calcium levels in neurons. We show here that β2*-nAChRs are essential for acquisition of normal numbers of dendritic spines during development. Mice constitutively lacking the β2-nAChR gene have fewer dendritic spines than do age-matched wild-type mice at all times examined. Activation of β2*-nAChRs by nicotine either in vivo or in organotypic slice culture quickly elevates the number of spines. RNA interference studies both in vivo and in organotypic culture demonstrate that the β2*-nAChRs act in a cell-autonomous manner to increase the number of spines. The increase depends on intracellular calcium and activation of calcium, calmodulin-dependent protein kinase II. Absence of β2*-nAChRs in vivo causes a disproportionate number of glutamatergic synapses to be localized on dendritic shafts, rather than on spines as occurs in wild type. This shift in synapse location is found both in the hippocampus and cortex, indicating the breadth of the effect. Because spine synapses differ from shaft synapses in their signaling capabilities, the shift observed is likely to have significant consequences for network function.

POST-PUBERTAL DECREASE IN HIPPOCAMPAL DENDRITIC SPINES OF FEMALE RATS

PubMed Central